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Archive for the ‘SARS-CoV-2 Viral Variants’ Category


Thriving Vaccines and Research: Weizmann Institute Coronavirus Research Development

Reporter: Amandeep Kaur, B.Sc., M.Sc.

In early February, Prof. Eran Segal updated in one of his tweets and mentioned that “We say with caution, the magic has started.”

The article reported that this statement by Prof. Segal was due to decreasing cases of COVID-19, severe infection cases and hospitalization of patients by rapid vaccination process throughout Israel. Prof. Segal emphasizes in another tweet to remain cautious over the country and informed that there is a long way to cover and searching for scientific solutions.

A daylong webinar entitled “COVID-19: The epidemic that rattles the world” was a great initiative by Weizmann Institute to share their scientific knowledge about the infection among the Israeli institutions and scientists. Prof. Gideon Schreiber and Dr. Ron Diskin organized the event with the support of the Weizmann Coronavirus Response Fund and Israel Society for Biochemistry and Molecular Biology. The speakers were invited from the Hebrew University of Jerusalem, Tel-Aviv University, the Israel Institute for Biological Research (IIBR), and Kaplan Medical Center who addressed the molecular structure and infection biology of the virus, treatments and medications for COVID-19, and the positive and negative effect of the pandemic.

The article reported that with the emergence of pandemic, the scientists at Weizmann started more than 60 projects to explore the virus from different range of perspectives. With the help of funds raised by communities worldwide for the Weizmann Coronavirus Response Fund supported scientists and investigators to elucidate the chemistry, physics and biology behind SARS-CoV-2 infection.

Prof. Avi Levy, the coordinator of the Weizmann Institute’s coronavirus research efforts, mentioned “The vaccines are here, and they will drastically reduce infection rates. But the coronavirus can mutate, and there are many similar infectious diseases out there to be dealt with. All of this research is critical to understanding all sorts of viruses and to preempting any future pandemics.”

The following are few important projects with recent updates reported in the article.

Mapping a hijacker’s methods

Dr. Noam Stern-Ginossar studied the virus invading strategies into the healthy cells and hijack the cell’s systems to divide and reproduce. The article reported that viruses take over the genetic translation system and mainly the ribosomes to produce viral proteins. Dr. Noam used a novel approach known as ‘ribosome profiling’ as her research objective and create a map to locate the translational events taking place inside the viral genome, which further maps the full repertoire of viral proteins produced inside the host.

She and her team members grouped together with the Weizmann’s de Botton Institute and researchers at IIBR for Protein Profiling and understanding the hijacking instructions of coronavirus and developing tools for treatment and therapies. Scientists generated a high-resolution map of the coding regions in the SARS-CoV-2 genome using ribosome-profiling techniques, which allowed researchers to quantify the expression of vital zones along the virus genome that regulates the translation of viral proteins. The study published in Nature in January, explains the hijacking process and reported that virus produces more instruction in the form of viral mRNA than the host and thus dominates the translation process of the host cell. Researchers also clarified that it is the misconception that virus forced the host cell to translate its viral mRNA more efficiently than the host’s own translation, rather high level of viral translation instructions causes hijacking. This study provides valuable insights for the development of effective vaccines and drugs against the COVID-19 infection.

Like chutzpah, some things don’t translate

Prof. Igor Ulitsky and his team worked on untranslated region of viral genome. The article reported that “Not all the parts of viral transcript is translated into protein- rather play some important role in protein production and infection which is unknown.” This region may affect the molecular environment of the translated zones. The Ulitsky group researched to characterize that how the genetic sequence of regions that do not translate into proteins directly or indirectly affect the stability and efficiency of the translating sequences.

Initially, scientists created the library of about 6,000 regions of untranslated sequences to further study their functions. In collaboration with Dr. Noam Stern-Ginossar’s lab, the researchers of Ulitsky’s team worked on Nsp1 protein and focused on the mechanism that how such regions affect the Nsp1 protein production which in turn enhances the virulence. The researchers generated a new alternative and more authentic protocol after solving some technical difficulties which included infecting cells with variants from initial library. Within few months, the researchers are expecting to obtain a more detailed map of how the stability of Nsp1 protein production is getting affected by specific sequences of the untranslated regions.

The landscape of elimination

The article reported that the body’s immune system consists of two main factors- HLA (Human Leukocyte antigen) molecules and T cells for identifying and fighting infections. HLA molecules are protein molecules present on the cell surface and bring fragments of peptide to the surface from inside the infected cell. These peptide fragments are recognized and destroyed by the T cells of the immune system. Samuels’ group tried to find out the answer to the question that how does the body’s surveillance system recognizes the appropriate peptide derived from virus and destroy it. They isolated and analyzed the ‘HLA peptidome’- the complete set of peptides bound to the HLA proteins from inside the SARS-CoV-2 infected cells.

After the analysis of infected cells, they found 26 class-I and 36 class-II HLA peptides, which are present in 99% of the population around the world. Two peptides from HLA class-I were commonly present on the cell surface and two other peptides were derived from coronavirus rare proteins- which mean that these specific coronavirus peptides were marked for easy detection. Among the identified peptides, two peptides were novel discoveries and seven others were shown to induce an immune response earlier. These results from the study will help to develop new vaccines against new coronavirus mutation variants.

Gearing up ‘chain terminators’ to battle the coronavirus

Prof. Rotem Sorek and his lab discovered a family of enzymes within bacteria that produce novel antiviral molecules. These small molecules manufactured by bacteria act as ‘chain terminators’ to fight against the virus invading the bacteria. The study published in Nature in January which reported that these molecules cause a chemical reaction that halts the virus’s replication ability. These new molecules are modified derivates of nucleotide which integrates at the molecular level in the virus and obstruct the works.

Prof. Sorek and his group hypothesize that these new particles could serve as a potential antiviral drug based on the mechanism of chain termination utilized in antiviral drugs used recently in the clinical treatments. Yeda Research and Development has certified these small novel molecules to a company for testing its antiviral mechanism against SARS-CoV-2 infection. Such novel discoveries provide evidences that bacterial immune system is a potential repository of many natural antiviral particles.

Resolving borderline diagnoses

Currently, Real-time Polymerase chain reaction (RT-PCR) is the only choice and extensively used for diagnosis of COVID-19 patients around the globe. Beside its benefits, there are problems associated with RT-PCR, false negative and false positive results and its limitation in detecting new mutations in the virus and emerging variants in the population worldwide. Prof. Eran Elinavs’ lab and Prof. Ido Amits’ lab are working collaboratively to develop a massively parallel, next-generation sequencing technique that tests more effectively and precisely as compared to RT-PCR. This technique can characterize the emerging mutations in SARS-CoV-2, co-occurring viral, bacterial and fungal infections and response patterns in human.

The scientists identified viral variants and distinctive host signatures that help to differentiate infected individuals from non-infected individuals and patients with mild symptoms and severe symptoms.

In Hadassah-Hebrew University Medical Center, Profs. Elinav and Amit are performing trails of the pipeline to test the accuracy in borderline cases, where RT-PCR shows ambiguous or incorrect results. For proper diagnosis and patient stratification, researchers calibrated their severity-prediction matrix. Collectively, scientists are putting efforts to develop a reliable system that resolves borderline cases of RT-PCR and identify new virus variants with known and new mutations, and uses data from human host to classify patients who are needed of close observation and extensive treatment from those who have mild complications and can be managed conservatively.

Moon shot consortium refining drug options

The ‘Moon shot’ consortium was launched almost a year ago with an initiative to develop a novel antiviral drug against SARS-CoV-2 and was led by Dr. Nir London of the Department of Chemical and Structural Biology at Weizmann, Prof. Frank von Delft of Oxford University and the UK’s Diamond Light Source synchroton facility.

To advance the series of novel molecules from conception to evidence of antiviral activity, the scientists have gathered support, guidance, expertise and resources from researchers around the world within a year. The article reported that researchers have built an alternative template for drug-discovery, full transparency process, which avoids the hindrance of intellectual property and red tape.

The new molecules discovered by scientists inhibit a protease, a SARS-CoV-2 protein playing important role in virus replication. The team collaborated with the Israel Institute of Biological Research and other several labs across the globe to demonstrate the efficacy of molecules not only in-vitro as well as in analysis against live virus.

Further research is performed including assaying of safety and efficacy of these potential drugs in living models. The first trial on mice has been started in March. Beside this, additional drugs are optimized and nominated for preclinical testing as candidate drug.

Source: https://www.weizmann.ac.il/WeizmannCompass/sections/features/the-vaccines-are-here-and-research-abounds

Other related articles were published in this Open Access Online Scientific Journal, including the following:

Identification of Novel genes in human that fight COVID-19 infection

Reporter: Amandeep Kaur, B.Sc., M.Sc. (ept. 5/2021)

https://pharmaceuticalintelligence.com/2021/04/19/identification-of-novel-genes-in-human-that-fight-covid-19-infection/

Fighting Chaos with Care, community trust, engagement must be cornerstones of pandemic response

Reporter: Amandeep Kaur, B.Sc., M.Sc. (ept. 5/2021)

https://pharmaceuticalintelligence.com/2021/04/13/fighting-chaos-with-care/

T cells recognize recent SARS-CoV-2 variants

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2021/03/30/t-cells-recognize-recent-sars-cov-2-variants/

Need for Global Response to SARS-CoV-2 Viral Variants

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2021/02/12/need-for-global-response-to-sars-cov-2-viral-variants/

Mechanistic link between SARS-CoV-2 infection and increased risk of stroke using 3D printed models and human endothelial cells

Reporter: Adina Hazan, PhD

https://pharmaceuticalintelligence.com/2020/12/28/mechanistic-link-between-sars-cov-2-infection-and-increased-risk-of-stroke-using-3d-printed-models-and-human-endothelial-cells/

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Identification of Novel genes in human that fight COVID-19 infection

Reporter: Amandeep Kaur, B.Sc., M.Sc. (ept. 5/2021)

Scientists have recognized human genes that fight against the SARS-CoV-2 viral infection. The information about genes and their function can help to control infection and aids the understanding of crucial factors that causes severe infection. These novel genes are related to interferons, the frontline fighter in our body’s defense system and provide options for therapeutic strategies.

The research was published in the journal Molecular Cell.

Sumit K. Chanda, Ph.D., professor and director of the Immunity and Pathogenesis Program at Sanford Burnham Prebys reported in the article that they focused on better understanding of the cellular response and downstream mechanism in cells to SARS-CoV-2, including the factors which causes strong or weak response to viral infection. He is the lead author of the study and explained that in this study they have gained new insights into how the human cells are exploited by invading virus and are still working towards finding any weak point of virus to develop new antivirals against SARS-CoV-2.

With the surge of pandemic, researchers and scientists found that in severe cases of COVID-19, the response of interferons to SARS-CoV-2 viral infection is low. This information led Chanda and other collaborators to search for interferon-stimulated genes (ISGs), are genes in human which are triggered by interferons and play important role in confining COVID-19 infection by controlling their viral replication in host.

The investigators have developed laboratory experiments to identify ISGs based on the previous knowledge gathered by the outbreak of SARS-CoV-1 from 2002-2004 which was similar to COVID-19 pandemic caused by SARS-CoV-2 virus.

The article reports that Chanda mentioned “we found that 65 ISGs controlled SAR-CoV-2 infection, including some that inhibited the virus’ ability to enter cells, some that suppressed manufacture of the RNA that is the virus’s lifeblood, and a cluster of genes that inhibited assembly of the virus.” They also found an interesting fact about ISGs that some of these genes revealed control over unrelated viruses, such as HIV, West Nile and seasonal flu.

Laura Martin-Sancho, Ph.D., a senior postdoctoral associate in the Chanda lab and first author of the study reported in the article that they identified 8 different ISGs that blocked the replication of both SARS-CoV-1 and CoV-2 in the subcellular compartments responsible for packaging of proteins, which provide option to exploit these vulnerable sites to restrict infection. They are further investigating whether the genetic variability within the ISGs is associated with COVID-19 severity.

The next step for researchers will be investigating and observing the biology of variants of SARS-CoV-2 that are evolving and affecting vaccine efficacy. Martin-Sancho mentioned that their lab has already started gathering all the possible variants for further investigation.

“It’s vitally important that we don’t take our foot off the pedal of basic research efforts now that vaccines are helping control the pandemic,” reported in the article by Chanda.

“We’ve come so far so fast because of investment in fundamental research at Sanford Burnham Prebys and elsewhere, and our continued efforts will be especially important when, not if, another viral outbreak occurs,” concluded Chanda.

Source: https://medicalxpress.com/news/2021-04-covid-scientists-human-genes-infection.html

Reference: Laura Martin-Sancho et al. Functional Landscape of SARS-CoV-2 Cellular Restriction, Molecular Cell (2021). DOI: 10.1016/j.molcel.2021.04.008

Other related articles were published in this Open Access Online Scientific Journal, including the following:

Fighting Chaos with Care, community trust, engagement must be cornerstones of pandemic response

Reporter: Amandeep Kaur

https://pharmaceuticalintelligence.com/2021/04/13/fighting-chaos-with-care/

Mechanism of Thrombosis with AstraZeneca and J & J Vaccines: Expert Opinion by Kate Chander Chiang & Ajay Gupta, MD

Reporter & Curator: Dr. Ajay Gupta, MD

https://pharmaceuticalintelligence.com/2021/04/14/mechanism-of-thrombosis-with-astrazeneca-and-j-j-vaccines-expert-opinion-by-kate-chander-chiang-ajay-gupta-md/

T cells recognize recent SARS-CoV-2 variants

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2021/03/30/t-cells-recognize-recent-sars-cov-2-variants/

Need for Global Response to SARS-CoV-2 Viral Variants

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2021/02/12/need-for-global-response-to-sars-cov-2-viral-variants/

Mechanistic link between SARS-CoV-2 infection and increased risk of stroke using 3D printed models and human endothelial cells

Reporter: Adina Hazan, PhD

https://pharmaceuticalintelligence.com/2020/12/28/mechanistic-link-between-sars-cov-2-infection-and-increased-risk-of-stroke-using-3d-printed-models-and-human-endothelial-cells/

Read Full Post »


 

 

Mechanism of thrombosis with AstraZeneca and J & J vaccines: Expert Opinion by Kate Chander Chiang & Ajay Gupta, MD

UPDATED on 4/15/2021


Atul Gawande@Atul_Gawande
·

Why wait for more info? A new case of cerebral sinus venus thrombosis was reported in a 25 year old man who became critically ill from a cerebral hemorrhage. And for women age 20-50, CSVT occurred in 1 in 13,000, or 4-15X higher than background.

UPDATED on 4/14/2021

How UK doctor linked rare blood-clotting to AstraZeneca Covid jab

https://www.theguardian.com/society/2021/apr/13/how-uk-doctor-marie-scully-blood-clotting-link-astrazeneca-covid-jab-university-college-london-hospital

From: “Gupta, Ajay” <ajayg1@hs.uci.edu>

Date: Wednesday, April 14, 2021 at 10:33 AM

To: “Aviva Lev-Ari, PhD, RN” <AvivaLev-Ari@alum.berkeley.edu>

Cc: Kate Chiang <kcscience777@gmail.com>

Subject: Mechanism of thrombosis with AstraZeneca and J & J vaccines

https://www.fda.gov/news-events/press-announcements/joint-cdc-and-fda-statement-johnson-johnson-covid-19-vaccine

We have put together the following mechanism for thrombosis including central vein sinus thrombosis as a complication of both J&J and the AstraZeneca vaccines. This unifying mechanism explains the predilection of cerebral veins and higher risk in younger women. Please share your thoughts on the proposed mechanism.

We have submitted the attached manuscript to SSRN.  Sharing this promptly considering the public health significance.

Thanks

Figure 1. AstraZeneca or Janssen COVID-19 vaccine induced thromboinflammation and cerebral venous sinus thrombosis (CVST)-Proposed Mechanisms: Adenovirus carrier delivers SARS-CoV-2 DNA encoding the Spike (S) protein to the lung megakaryocytes via the coxsackie-adenovirus receptor (CAR). Spike protein induces COX-2 expression in megakaryocytes leading to megakaryocyte activation, biogenesis of activated platelets that express COX-2 and generate thromboxane A2 (TxA2). Cerebral vein sinus endothelial cells express podoplanin, a natural ligand for CLEC2 receptors on platelets. Platelets traversing through the cerebral vein sinuses would be further activated by TxA2 dependent podoplanin-CLEC2 signaling, leading to release of extracellular vesicles, thereby promoting CLEC5A and TLR2 mediated neutrophil activation, thromboinflammation, CVST, and thromboembolism in other vascular beds. Young age and female gender are associated with increased TxA2 generation and platelet activation respectively, and hence increased risk of thromboembolic complications following vaccination.

Best regards,

Ajay

Ajay Gupta, M.B.,B.S., M.D.

Clinical Professor,

Division of Nephrology, Hypertension and Kidney Transplantation

University of California Irvine  

President & CSO, KARE Biosciences (www.karebio.com)

E-mail:     ajayg1@hs.uci.edu

Cell:         1 (562) 412-6259

Office:     1 (562) 419-7029

PERSPECTIVE 

Title: SARS-CoV-2 vaccination induced thrombosis: Is chemoprophylaxis with antiplatelet agents warranted? 

Guest Authors: 

Kate Chander Chiang1 

Ajay Gupta, MBBS, MD1,2 

Affiliations 

(1) KARE Biosciences, Orange, CA 92869 

(2) Department of Medicine, University of California Irvine (UCI) School of Medicine, Orange, CA 92868 

*Corresponding author: 

Ajay Gupta, MBBS, MD 

Clinical Professor of Medicine, 

Division of Nephrology, Hypertension and Kidney Transplantation 

University of California Irvine (UCI) School of Medicine, 

Orange, CA 92868 

Tel: +1 (562) 412-6259 

E-mail: ajayg1@hs.uci.edu 

Word Count 

Abstract: 359 

Main Body: 1,648 

Funding: No funding was required. 

Conflict of Interest: AG and KCC have filed a patent for use of Ramatroban as an anti-thrombotic and immune modulator in SARS-CoV-2 infection. The patents have been licensed to KARE Biosciences. KCC is an employee of KARE Biosciences. 

Author Contributions: AG and KCC conceptualized, created the framework, wrote and reviewed the manuscript. 

Abbreviations: TxA2, thromboxane A2; DIC, disseminated intravascular coagulopathy; COX, cyclooxygenase; TTP, thrombotic thrombocytopenic purpura; CVST, cerebral venous sinus thrombosis; CLEC, C-type lectin-like receptor; TLR, toll-like receptor; CAR, coxsackievirus and adenovirus receptor; COVID-19, coronavirus disease 2019; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2 2 

ABSTRACT 

The COVID-19 vaccines, Vaxzevria® (AstraZeneca) and the Janssen vaccine (Johnson & Johnson) are highly effective but associated with rare thrombotic complications. These vaccines are comprised of recombinant, replication incompetent, chimpanzee adenoviral vectors encoding the Spike (S) glycoprotein of SARS-CoV-2. The adenovirus vector infects epithelial cells expressing the coxsackievirus and adenovirus receptor (CAR). The S glycoprotein of SARS-CoV-2 is expressed locally stimulating neutralizing antibody and cellular immune responses, which protect against COVID-19. The immune responses are highly effective in preventing symptomatic disease in adults irrespective of age, gender or ethnicity. However, both vaccines have been associated with thromboembolic events including cerebral venous sinus thrombosis (CVST). Megakaryocytes also express CAR, leading us to postulate adenovirus vector uptake and expression of spike glycoprotein by megakaryocytes. Spike glycoprotein induces expression of cyclooxygenase -2 (COX-2), leading to generation of thromboxane A2 (TxA2). TxA2 promotes megakaryocyte activation, biogenesis of activated platelets and thereby increased thrombogenicity. Cerebral vein sinus endothelial cells express podoplanin, a natural ligand for CLEC2 receptors on platelets. Platelets traversing through the cerebral vein sinuses would be further activated by TxA2 dependent podoplanin-CLEC2 signaling, leading to CVST. The mechanisms proposed are consistent with the following clinical observations. First, a massive increase in TxA2 generation promotes platelet activation and thromboinflammation in COVID-19 patients. Second, TxA2 generation and platelet activation is increased in healthy women compared to men, and in younger mice compared to older mice; and, younger age and female gender appear to be associated with increased risk of thromboembolism as a complication of adenoviral vector based COVID-19 vaccine. The roll out of both AstraZeneca and Janssen vaccines has been halted for adults under 30-60 years of age in many countries. We propose that antiplatelet agents targeting TxA2 receptor signaling should be considered for chemoprophylaxis when administering the adenovirus based COVID-19 vaccines to adults under 30-60 years of age. In many Asian and African countries, only adenovirus-based COVID-19 vaccines are available at present. A short course of an antiplatelet agent such as aspirin could allow millions to avail of the benefits of the AstraZeneca and Janssen COVID-19 vaccines which could be otherwise either denied to them or put them at undue risk of thromboembolic complications. 

Keywords: SARS-CoV-2, COVID-19, Vaxzevria, COVISHIELD, Janssen COVID-19 vaccine, Johnson & Johnson vaccine, AstraZeneca vaccine, AZD1222, thrombosis, cerebral venous sinus thrombosis, thromboembolism, aspirin, antiplatelet agents, thromboxane, COX-2, disseminated intravascular coagulation, thrombocytopenia, thrombotic thrombocytopenia, CLEC2, megakaryocyte 3 

COVID-19 disease is caused by a novel positive-strand RNA coronavirus (SARS-CoV-2), which belongs to the Coronaviridae family, along with the severe acute respiratory syndrome (SARS) and the Middle East respiratory syndrome (MERS) coronaviruses.1 The genome of these viruses encodes several non-structural and structural proteins, including spike (S), envelope (E), membrane (M), and nucleocapsid (N) proteins.2 The majority of the vaccines for COVID-19 that employ administration of viral antigens or viral gene sequences aim to induce neutralizing antibodies against the viral spike protein (S), preventing uptake through the ACE2 receptor, and thereby blocking infection.3 

The Janssen COVID-19 vaccine (Johnson & Johnson) is comprised of a recombinant, replication- incompetent Ad26 vector, encoding a stabilized variant of the SARS-CoV-2 Spike (S) protein. The ChAdOx1 nCoV-19 vaccine (AZD1222, Vaxzevria®) was developed at Oxford University and consists of a replication-deficient chimpanzee adenoviral vector ChAdOx1, encoding the S protein.4 In US Phase III trials, Vaxzevria has been demonstrated to have 79% efficacy at preventing symptomatic COVID-19, and 100% efficacy against severe or critical disease and hospitalization, with comparable efficacy across ethnicity, gender and age.5 However, Vaxzevria has been associated with thrombotic and embolic events including disseminated intravascular coagulation (DIC) and cerebral venous sinus thrombosis (CVST), occurring within 14 days after vaccination, mostly in people under 55 years of age, the majority of whom have been women.6 Data from Europe suggests that the event rate for thromboembolic events may be about 10 per million vaccinated. Antibodies to platelet factor 4/heparin complexes have been recently reported in a few patients.7 However, the significance of this finding remains to be established. As of April 12, 2021, about 6.8 million doses of the Janssen vaccine have been administered in the U.S.8 CDC and FDA are reviewing data involving six reported U.S. cases of CVST in combination with thrombocytopenia.8 All six cases occurred among women between the ages of 18 and 48, and symptoms occurred 6 to 13 days after vaccination.8 

SARS-CoV-2 is known to cause thromboinflammation leading to thrombotic microangiopathy, pulmonary thrombosis, pedal acro-ischemia (“COVID-toes”), arterial clots, strokes, cardiomyopathy, coronary and systemic vasculitis, deep venous thrombosis, pulmonary embolism, and microvascular thrombosis in renal, cardiac and brain vasculature.9-14 Cerebral venous sinus thrombosis (CVST) has also been reported in COVID-19 patients.15 Amongst 34,331 hospitalized COVID-19 patients, CVST was diagnosed in 28.16 In a multicenter, multinational, cross sectional, retrospective study of 8 patients diagnosed with CVST and COVID-19, seven were women.17 In another series of 41 patients with COVID-19 and CVST, the average age was about 50 years (SD, 16.5 years).17 The pathobiology of thrombotic events associated with the AstraZeneca vaccine should be viewed in the context of mechanisms underlying thromboinflammation that complicates SARS-CoV-2 infection and COVID-19 disease. 

A. Role of COX-2 and thromboxane A2 in thromboinflammation complicating adenovirus based COVID-19 vaccine encoding the Spike protein of SARS-CoV-2 

Thromboinflammation in COVID-19 seems to be primarily caused by endothelial, platelet and neutrophil activation, platelet-neutrophil aggregates and release of neutrophil extracellular traps (NETs).13,18 Platelet activation in COVID-19 is fueled by a lipid storm characterized by massive increases in thromboxane A2 (TxA2) levels in the blood and bronchoalveolar lavage fluid.19,20 Cyclooxygenase (COX) enzymes catalyze the first step in the biosynthesis of TxA2 from arachidonic acid, and COX-2 expression is induced by the spike (S) protein of coronaviruses.21 We postulate that an aberrant increase in TxA2 generation induced by the spike protein expression from the AstraZeneca vaccine leads to thromboinflammation, thromboembolism and CVST. 4 

The support for the above proposed mechanism comes from the following observations. First, when mice of different age groups were infected with SARS-CoV virus, the generation of TxA2 was markedly increased in younger mice compared to middle aged mice.22 Furthermore, in children with asymptomatic or mildly symptomatic SARS-CoV-2 infection, microvascular thrombosis and thrombotic microangiopathy occur early in infection.20 These observations are consistent with the higher risk for thrombosis in adults under 60 years of age, compared with the older age group.6,7 Second, platelets from female mice are much more reactive than from male mice.23 Furthermore, TxA2 generation, TxA2-platelet interaction and activation is increased in women compared to men.24,25 These observations are consistent with disproportionately increased risk of thrombosis in women following AstraZeneca and Janssen COVID-19 vaccines. 

The adenoviral vector ChAdOx1, containing nCoV-19 spike protein gene, infects host cells through the coxsackievirus and adenovirus receptor (CAR).26 CAR-dependent cell entry of the viral vector allows insertion of the SARS-CoV-2 spike protein gene and expression of Spike protein by host cells (Figure 1). CAR is primarily expressed on epithelial tight junctions.27 CAR expression has also been reported in platelets,28 and since platelets are anucleate cells CAR expression by megakaryocytes can be inferred. Therefore, AstraZeneca and Janssen vaccines would be expected to induce expression of Spike protein in megakaryocytes and platelets (Figure 1). 

Spike protein of coronaviruses in known to induce COX-2 gene expression.21,29 COX-2 expression is induced during normal human megakaryopoiesis and characterizes newly formed platelets.30 While in healthy controls <10% of circulating platelets express COX-2, in patients with high platelet generation, up to 60% of platelets express COX-2.30 Generation of TxA2 by platelets is markedly suppressed by COX-2 inhibition in patients with increased megakaryopoiesis versus healthy subjects.30 Therefore, we postulate that expression of Spike protein induces COX-2 expression and generation of thromboxane A2 by megakaryocytes. TxA2 promotes biogenesis of activated platelets expressing COX-2. Platelet TxA2 generation leads to platelet activation and aggregation, and thereby thromboinflammation (Figure 1). 

Extravascular spaces of the lungs comprise populations of mature and immature megakaryocytes that originate from the bone marrow, such that lungs are a major site of platelet biogenesis, accounting for approximately 50% of total platelet production or about 10 million platelets per hour.31 More than 1 million extravascular megakaryocytes have been observed in each lung of transplant mice.31 Following intramuscular injection of the AstraZeneca and Janssen vaccines, the adenovirus vector will traverse the veins and lymphatics to be delivered to the pulmonary circulation thereby exposing lung megakaryocytes in the first pass. Interestingly, under thrombocytopenic conditions, haematopoietic progenitors migrate out of the lung to repopulate the bone marrow and completely reconstitute blood platelet counts.31 

B. Predilection of cerebral venous sinuses for thrombosis following vaccination 

Recent studies have demonstrated that arterial, venous and sinusoidal endothelial cells in the brain uniquely express markers of the lymphatic endothelium including podoplanin.32 Podoplanin serves as a ligand for CLEC2 receptors on platelets.33 Thromboxane A2 dependent CLEC2 signaling leads to platelet activation (Figure 1), while a TxA2 receptor antagonist nearly abolish CLEC2 signaling and platelet activation.33 TxA2 dependent CLEC2 signaling promotes release of exosomes and microvesicles from platelets, leading to activation of CLEC5A and TLR2 receptors respectively on neutrophils, neutrophil activation and release of neutrophil extracellular traps (NETs) (Figure 1).34 Neutrophil activation, more than platelet activation, is associated with thrombotic complications in COVID-19.13,18,35 As proposed above, the expression of podoplanin, a unique molecular signature of cerebral endothelial cells, may be responsible for the predilection of brain vascular bed to thromboinflammation and CVST as a complication of COVID-19 vaccines. 5 

C. Chemoprophylaxis with antiplatelet agents 

In animal models of endotoxin mediated endothelial injury and thromboinflammation, antagonism of TxA2 signaling prevents ARDS, reduces myocardial damage and increases survival.36-38 

Considering the key role played by platelets in thromboinflammation, we propose consideration of antiplatelet agents, either aspirin or TxA2 receptor antagonists, as chemoprophylactic agents when the AstraZeneca vaccine is administered to adults between 18 and 60 years of age.39 High bleeding risk because of another medical condition or medication would be contraindications to use of antiplatelet agents.39 Medical conditions that increase bleeding risk include previous gastrointestinal bleeding, peptic ulcer disease, blood clotting problems, and kidney disease.39 Medications that increase bleeding risk include nonsteroidal anti-inflammatory drugs, steroids, and other anticoagulants or anti-platelet agents.39 Aspirin appears to be safe in COVID-19. In a retrospective observational study in hospitalized patients with COVID-19, low-dose aspirin was found to be effective in reducing morbidity and mortality; and was not associated with any safety issues including major bleeding.40 Therefore, aspirin is likely to be safe as an adjunct to COVID-19 vaccines even in the event of a subsequent infection with SARS-CoV-2 virus. 

Can aspirin influence the host immune response to the COVID-19 vaccines? This issue merits further investigation. When healthy adults > 65 years of age were given influenza vaccine and randomized to receive 300 mg aspirin or placebo on days 1, 2, 3, 5 and 7, the aspirin group showed 4-fold or greater rise in influenza specific antibodies.41 The risk-benefit analysis, based on above information, suggests that a one to three week course of low-dose aspirin merits consideration in order to prevent the thromboembolic events associated with the AstraZeneca vaccine. 

SUMMARY 

Thromboembolic disease including disseminated intravascular coagulation and cerebral venous sinus thrombosis have been reported in association with AstraZeneca and Janssen COVID-19 vaccines. Many countries have halted use of these vaccines either entirely or for adults under 30 to 60 years of age. European and North American countries generally have access to mRNA vaccines. However, in Asian and African countries the choices are limited to adenovirus based COVID-19 vaccines. The governments in such countries are forging ahead with vaccinating all adults, including those under 60 years of age, with Vaxzevria, Covishield (the version of Vaxzevria manufactured by the Serum Institute of India) or the Janssen vaccines. This has led to grave concern and anxiety amongst the citizens and medical professionals. Considering the profound global public health implications of limiting the use of these vaccines, it is critical to understand the pathobiology of vaccination induced thrombotic events in order to guide strategies aimed at prevention. In this regard, studies are urgently needed to examine lipid mediators and thromboxane A2 – platelet axis following vaccination with these vaccines, compared with mRNA vaccines. The risk-benefit analysis based on information presented here suggests that chemoprophylaxis using a short course of low-dose aspirin in adults under 60 years of age may be justified in conjunction with adenovirus based COVID-19 vaccines in order to prevent thromboembolic events and enhance safety. 6 

Figure 1. AstraZeneca or Janssen COVID-19 vaccine induced thromboinflammation and cerebral venous sinus thrombosis (CVST)-Proposed Mechanisms: Adenovirus carrier delivers SARS-CoV-2 DNA encoding the Spike (S) protein to the lung megakaryocytes via the coxsackie-adenovirus receptor (CAR). Spike protein induces COX-2 expression in megakaryocytes leading to megakaryocyte activation, biogenesis of activated platelets that express COX-2 and generate thromboxane A2 (TxA2). Cerebral vein sinus endothelial cells express podoplanin, a natural ligand for CLEC2 receptors on platelets. Platelets traversing through the cerebral vein sinuses would be further activated by TxA2 dependent podoplanin-CLEC2 signaling, leading to release of extracellular vesicles, thereby promoting CLEC5A and TLR2 mediated neutrophil activation, thromboinflammation, CVST, and thromboembolism in other vascular beds. Young age and female gender are associated with increased TxA2 generation and platelet activation respectively, and hence increased risk of thromboembolic complications following vaccination. 

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18. Petito E, Falcinelli E, Paliani U, et al. Association of Neutrophil Activation, More Than Platelet Activation, With Thrombotic Complications in Coronavirus Disease 2019. The Journal of Infectious Diseases. 2020. 8 

19. Archambault A-S, Zaid Y, Rakotoarivelo V, et al. Lipid storm within the lungs of severe COVID-19 patients: Extensive levels of cyclooxygenase and lipoxygenase-derived inflammatory metabolites. medRxiv. 2020:2020.2012.2004.20242115. 

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25. Eikelboom JW, Hirsh J, Weitz JI, Johnston M, Yi Q, Yusuf S. Aspirin-resistant thromboxane biosynthesis and the risk of myocardial infarction, stroke, or cardiovascular death in patients at high risk for cardiovascular events. Circulation. 2002;105(14):1650-1655. 

26. Cohen CJ, Xiang ZQ, Gao G-P, Ertl HCJ, Wilson JM, Bergelson JM. Chimpanzee adenovirus CV-68 adapted as a gene delivery vector interacts with the coxsackievirus and adenovirus receptor. Journal of General Virology. 2002;83(1):151-155. 

27. Cohen CJ, Shieh JT, Pickles RJ, Okegawa T, Hsieh JT, Bergelson JM. The coxsackievirus and adenovirus receptor is a transmembrane component of the tight junction. Proc Natl Acad Sci U S A. 2001;98(26):15191-15196. 

28. Assinger A. Platelets and infection – an emerging role of platelets in viral infection. Front Immunol. 2014;5:649. 

29. Yan X, Hao Q, Mu Y, et al. Nucleocapsid protein of SARS-CoV activates the expression of cyclooxygenase-2 by binding directly to regulatory elements for nuclear factor-kappa B and CCAAT/enhancer binding protein. Int J Biochem Cell Biol. 2006;38(8):1417-1428. 

30. Rocca B, Secchiero P, Ciabattoni G, et al. Cyclooxygenase-2 expression is induced during human megakaryopoiesis and characterizes newly formed platelets. Proc Natl Acad Sci U S A. 2002;99(11):7634-7639. 

31. Lefrançais E, Ortiz-Muñoz G, Caudrillier A, et al. The lung is a site of platelet biogenesis and a reservoir for haematopoietic progenitors. Nature. 2017;544(7648):105-109. 

32. Mezey É, Szalayova I, Hogden CT, et al. An immunohistochemical study of lymphatic elements in the human brain. Proceedings of the National Academy of Sciences. 2021;118(3):e2002574118. 

33. Badolia R, Inamdar V, Manne BK, Dangelmaier C, Eble JA, Kunapuli SP. G(q) pathway regulates proximal C-type lectin-like receptor-2 (CLEC-2) signaling in platelets. J Biol Chem. 2017;292(35):14516-14531. 9 

34. Sung P-S, Huang T-F, Hsieh S-L. Extracellular vesicles from CLEC2-activated platelets enhance dengue virus-induced lethality via CLEC5A/TLR2. Nature Communications. 2019;10(1). 

35. Ng H, Havervall S, Rosell A, et al. Circulating Markers of Neutrophil Extracellular Traps Are of Prognostic Value in Patients With COVID-19. Arteriosclerosis, Thrombosis, and Vascular Biology. 2021;41(2):988-994. 

36. Carey MA, Bradbury JA, Seubert JM, Langenbach R, Zeldin DC, Germolec DR. Contrasting Effects of Cyclooxygenase-1 (COX-1) and COX-2 Deficiency on the Host Response to Influenza A Viral Infection. The Journal of Immunology. 2005;175(10):6878-6884. 

37. Kuhl PG, Bolds JM, Loyd JE, Snapper JR, FitzGerald GA. Thromboxane receptor-mediated bronchial and hemodynamic responses in ovine endotoxemia. Am J Physiol. 1988;254(2 Pt 2):R310-319. 

38. Altavilla D, Canale P, Squadrito F, et al. Protective effects of BAY U 3405, a thromboxane A2 receptor antagonist, in endotoxin shock. Pharmacol Res. 1994;30(2):137-151. 

39. Peters AT, Mutharasan RK. Aspirin for Prevention of Cardiovascular Disease. JAMA. 2020;323(7):676. 

40. Chow JH, Khanna AK, Kethireddy S, et al. Aspirin Use Is Associated With Decreased Mechanical Ventilation, Intensive Care Unit Admission, and In-Hospital Mortality in Hospitalized Patients With Coronavirus Disease 2019. Anesthesia & Analgesia. 2021;132(4). 

41. Saleh E, Moody MA, Walter EB. Effect of antipyretic analgesics on immune responses to vaccination. Human Vaccines & Immunotherapeutics. 2016;12(9):2391-2402. 

SOURCE

From: “Gupta, Ajay” <ajayg1@hs.uci.edu>

Date: Wednesday, April 14, 2021 at 10:33 AM

To: “Aviva Lev-Ari, PhD, RN” <AvivaLev-Ari@alum.berkeley.edu>

This EXPERT OPINION is in response to:

From: Aviva Lev-Ari <AvivaLev-Ari@alum.berkeley.edu>
Date: Tuesday, April 13, 2021 at 9:03 AM
To: “Joel Shertok, PhD” <jshertok@yahoo.com>, “Stephen Williams, PhD” <sjwilliamspa@comcast.net>, “Prof. Marcus W Feldman” <mfeldman@stanford.edu>, “Irina Robu, PhD” <irina.stefania@gmail.com>, “Dr. Sudipta Saha” <sudiptasaha1977@gmail.com>, Aviva Lev-Ari <AvivaLev-Ari@alum.berkeley.edu>, “Dr. Larry Bernstein” <larry.bernstein@gmail.com>, “Ofer Markman, PhD” <oferm2020@gmail.com>, “Daniel Menzin (gmail)” <dmenzin@gmail.com>, Pnina Abir-Am <pnina.abiram@gmail.com>, Alan <alanalanf@gmail.com>, Justin MDMEPhD <jdpmdphd@gmail.com>, Inbar Ofer <ofer.i@northeastern.edu>, Aviva Lev-Ari <aviva.lev-ari@comcast.net>, Madison Davis <madisond2302@gmail.com>, Danielle Smolyar <dsmolyar@syr.edu>, “Adina Hazan, PhD” <adinathazan@gmail.com>, Gail Thornton <gailsthornton@yahoo.com>, Amandeep kaur <662amandeep@gmail.com>, Premalata Pati <premalata09@gmail.com>, “Ajay Gupta, MD” <charaklabs@outlook.com>, Saul Yedgar <saulye@ekmd.huji.ac.il>, Yigal Blum <yigalblum@gmail.com>, a el <AElRoeiy@gmail.com>, “Dr. Raphael Nir” <rnir@sbhsciences.com>, “George Tetz, MD, PhD” <gtetz@clstherapeutics.com>, “Dr. Martin R Schiller (CEO, Heligenics)” <heligenics@gmail.com>, “Jea Asio (Heligenics)” <JAsio@Heligenics.com>, Yakov Kogan <ykogan@tgv-biomed.com>, Haim Levkowitz <haim@cs.UML.edu>

Subject: APRIL 13. 2021 – J&J Statement – Out of an abundance of caution, the CDC and FDA have recommended a pause in the use of our vaccine. ->> Are there relations between these FINDINGS?

Johnson & Johnson Statement on COVID-19 Vaccine

NEW BRUNSWICK, N.J., April 13, 2021– The safety and well-being of the people who use our products is our number one priority. We are aware of an extremely rare disorder involving people with blood clots in combination with low platelets in a small number of individuals who have received our COVID-19 vaccine. The United States Centers for Disease Control (CDC) and Food and Drug Administration (FDA) are reviewing data involving six reported U.S. cases out of more than 6.8 million doses administered. Out of an abundance of caution, the CDC and FDA have recommended a pause in the use of our vaccine.

In addition, we have been reviewing these cases with European health authorities. We have made the decision to proactively delay the rollout of our vaccine in Europe.

We have been working closely with medical experts and health authorities, and we strongly support the open communication of this information to healthcare professionals and the public.

The CDC and FDA have made information available about proper recognition and management due to the unique treatment required with this type of blood clot. The health authorities advise that people who have received our COVID-19 vaccine and develop severe headache, abdominal pain, leg pain, or shortness of breath within three weeks after vaccination should contact their health care provider.

For more information on the Janssen COVID-19 vaccine, click here.

Please All send me your Expert Opinion on the relations between these FINDINGS?

Linking Thrombotic Thrombocytopenia to ChAdOx1 nCov-19 Vaccination, AstraZeneca | Leaders in Pharmaceutical Business Intelligence (LPBI) Group

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2021/04/12/linking-thrombotic-thrombocytopenia-to-chadox1-ncov-19-vaccination-astrazeneca/

Is SARS-COV2 Hijacking the Complement and Coagulation Systems?

Reporter: Stephen J. Williams, PhD

https://pharmaceuticalintelligence.com/2020/08/04/is-sars-cov2-hijacking-the-complement-and-coagulation-systems/

SAR-Cov-2 is probably a vasculotropic RNA virus affecting the blood vessels: Endothelial cell infection and endotheliitis in COVID-19

Reporter: Aviva Lev-Ari, PhD, RN 

https://pharmaceuticalintelligence.com/2020/06/01/sar-cov-2-is-probably-a-vasculotropic-rna-virus-affecting-the-blood-vessels-endothelial-cell-infection-and-endotheliitis-in-covid-19/

THANK YOU

Best regards,

Aviva

Aviva Lev-Ari, PhD, RN

Director & Founder

https://lnkd.in/eEyn69r

Leaders in Pharmaceutical Business Intelligence (LPBI) Group, Boston, MA, NJ, CA, PA, ME, DE, India, Israel & Canada

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Fighting Chaos with care, community trust, engagement must be cornerstones of pandemic response

Reporter: Amandeep Kaur, BSc, MSc (Exp. 6/2021)

According to the Global Health Security Index released by Johns Hopkins University in October 2019 in collaboration with Nuclear Threat Initiative (NTI) and The Economist Intelligence Unit (EIU), the United States was announced to be the best developed country in the world to tackle any pandemic or health emergency in future.

The table turned within in one year of outbreak of the novel coronavirus COVID-19. By the end of March 2021, the country with highest COVID-19 cases and deaths in the world was United States. According to the latest numbers provided by World Health Organization (WHO), there were more than 540,000 deaths and more than 30 million confirmed cases in the United States.

Joia Mukherjee, associate professor of global health and social medicine in the Blavatnik Institute at Harvard Medical School said,

“When we think about how to balance control of an epidemic over chaos, we have to double down on care and concern for the people and communities who are hardest hit”.

She also added that U.S. possess all the necessary building blocks required for a health system to work, but it lacks trust, leadership, engagement and care to assemble it into a working system.

Mukherjee mentioned about the issues with the Index that it undervalued the organized and integrated system which is necessary to help public meet their needs for clinical care. Another necessary element for real health safety which was underestimated was conveying clear message and social support to make effective and sustainable efforts for preventive public health measures.

Mukherjee is a chief medical officer at Partners In Health, an organization focused on strengthening community-based health care delivery. She is also a core member of HMS community members who play important role in constructing a more comprehensive response to the pandemic in all over the U.S. With years of experience, they are training global health care workers, analyzing the results and constructing an integrated health system to fight against the widespread health emergency caused by coronavirus all around the world.

Mukherjee encouraged to strengthen the consensus among the community to constrain this infectious disease epidemic. She suggested that validation of the following steps are crucial such as testing of the people with symptoms of infection with coronavirus, isolation of infected individuals by providing them with necessary resources and providing clinical treatment and care to those people who are in need. Mukherjee said, that community engagement and material support are not just idealistic goal rather these are essential components for functioning of health care system during an outburst of coronavirus.

Continued alertness such as social distancing and personal contact with infected individual is important because it is not possible to rapidly replace the old-school public health approaches with new advanced technologies like smart phone applications or biomedical improvements.

Public health specialists emphasized that the infection limitation is the only and most vital strategy for controlling the outbreak in near future, even if the population is getting vaccinated. It is crucial to slowdown the spread of disease for restricting the natural modification of more dangerous variants as that could potentially escape the immune protection mechanism developed by recently generated vaccines as well as natural immune defense systems.

Making Crucial connections

The treatment is more expensive and complicated in areas with less health facilities, said Paul Farmer, the Kolokotrones University Professor at Harvard and chair of the HMS Department of Global Health and Social Medicine. He called this situation as treatment nihilism. Due to shortage of resources, the maximum energy is focused in public health care and prevention efforts. U.S. has resources to cope up with the increasing demand of hospital space and is developing vaccines, but there is a form of containment nihilism- which means prevention and infection containment are unattainable- said by many experts.

Farmer said, integration of necessary elements such as clinical care, therapies, vaccines, preventive measures and social support into a single comprehensive plan is the best approach for a better response to COVID-19 disease. He understands the importance of community trust and integrated health care system for fighting against this pandemic, as being one of the founders of Partners In Health and have years of experience along with his colleagues from HMS and PIH in fighting epidemics of HIV, Ebola, cholera, tuberculosis, other infectious and non-infectious diseases.

PIH launched the Massachusetts Community Tracing Collaborative (CTC), which is an initiative of contact tracing statewide in partnership with several other state bodies, local boards of Health system and PIH. The CTC was setup in April 2020 in U.S. by Governor Charlie Baker, with leadership from HMS faculty, to build a unified response to COVID-19 and create a foundation for a long-term movement towards a more integrated community-based health care system.

The contact tracing involves reaching out to individuals who are COVID-19 positive, then further detect people who came in close contact with infected individuals and screen out people with coronavirus symptoms and encourage them to seek testing and take necessary precautions to break the chain of infection into the community.

In the initial phase of outbreak, the CTC group comprises of contact tracers and health care coordinators who spoke 23 different languages, including social workers, public health practitioners, nurses and staff members from local board health agencies with deep links to the communities they are helping. The CTC worked with 339 out of 351 state municipalities with local public health agencies relied completely on CTC whereas some cities and towns depend occasionally on CTC backup. According to a report, CTC members reached up to 80 percent of contact tracking in hard-hit and resource deprived communities such as New Bedford.

Putting COVID-19 in context

Based on generations of experience helping people surviving some of the deadliest epidemic and endemic outbreaks in places like Haiti, Mexico, Rwanda and Peru, the staff was alert that people with bad social and economic condition have less space to get quarantined and follow other public health safety measures and are most vulnerable people at high risk in the pandemic situation.

Infected individuals or individuals at risk of getting infected by SARS-CoV-2 had many questions regarding when to seek doctor’s help and where to get tested, reported by contact tracers. People were worried about being evicted from work for two weeks and some immigrants worried about basic supplies as they were away from their family and friends.

The CTC team received more than 7,000 requests for social support assistance in the initial three months. The staff members and contact tracers were actively connecting the resourceful individuals with the needy people and filling up the gap when there was shortage in their own resources.

Farmer said, “COVID is a misery-seeking missile that has targeted the most vulnerable.”

The reality that infected individuals concerned about lacking primary household items, food items and access to childcare, emphasizes the urgency of rudimentary social care and community support in fighting against the pandemic. Farmer said, to break the chain of infection and resume society it is mandatory to meet all the elementary needs of people.

“What kinds of help are people asking for?” Farmer said and added “it’s important to listen to what your patients are telling you.”

An outbreak of care

The launch of Massachusetts CTC with the support from PIH, started receiving requests from all around the country to assist initiating contact tracing procedures. In May, 2020 the organization announced the launch of a U.S. public health accompaniment to cope up with the asked need.

The unit has included team members in nearly 24 states and municipal health departments in the country and work in collaboration with local organizations. The technical support on things like choosing and implementing the tools and software for contact tracing was provided by PIH. To create awareness and provide new understanding more rapidly, a learning collaboration was established with more than 200 team members from more than 100 different organizations. The team worked to meet the needs of population at higher risk of infection by advocating them for a stronger and more reliable public health response.

The PIH public health team helped to train contact trackers in the Navajo nation and operate to strengthen the coordination between SARS-CoV-2 testing, efforts for precaution, clinical health care delivery and social support in vulnerable communities around the U.S.

“For us to reopen our schools, our churches, our workplaces,” Mukherjee said, “we have to know where the virus is spreading so that we don’t just continue on this path.”

SOURCE:

https://hms.harvard.edu/news/fighting-chaos-care?utm_source=Silverpop&utm_medium=email&utm_term=field_news_item_1&utm_content=HMNews04052021

Other related articles were published in this Open Access Online Scientific Journal, including the following:

T cells recognize recent SARS-CoV-2 variants

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2021/03/30/t-cells-recognize-recent-sars-cov-2-variants/

The WHO team is expected to soon publish a 300-page final report on its investigation, after scrapping plans for an interim report on the origins of SARS-CoV-2 — the new coronavirus responsible for killing 2.7 million people globally

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2021/03/27/the-who-team-is-expected-to-soon-publish-a-300-page-final-report-on-its-investigation-after-scrapping-plans-for-an-interim-report-on-the-origins-of-sars-cov-2-the-new-coronavirus-responsibl/

Need for Global Response to SARS-CoV-2 Viral Variants

Reporter: Aviva Lev-Ari, PhD, RN

https://pharmaceuticalintelligence.com/2021/02/12/need-for-global-response-to-sars-cov-2-viral-variants/

Mechanistic link between SARS-CoV-2 infection and increased risk of stroke using 3D printed models and human endothelial cells

Reporter: Adina Hazan, PhD

https://pharmaceuticalintelligence.com/2020/12/28/mechanistic-link-between-sars-cov-2-infection-and-increased-risk-of-stroke-using-3d-printed-models-and-human-endothelial-cells/

Artificial intelligence predicts the immunogenic landscape of SARS-CoV-2

Reporter: Irina Robu, PhD

https://pharmaceuticalintelligence.com/2021/02/04/artificial-intelligence-predicts-the-immunogenic-landscape-of-sars-cov-2/

Read Full Post »


Linking Thrombotic Thrombocytopenia to ChAdOx1 nCov-19 Vaccination, AstraZeneca

Reporter: Aviva Lev-Ari, PhD, RN

UPDATED on 4/13/2021

“Right now, these adverse events appear to be extremely rare,” Anne Schuchat, MD, principal deputy director of the CDC, and Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, said in a joint statement from the two agencies. “COVID-19 vaccine safety is a top priority for the federal government, and we take all reports of health problems following COVID-19 vaccination very seriously.”

STATEMENT BY J&J

Johnson & Johnson Statement on COVID-19 Vaccine

NEW BRUNSWICK, N.J., April 13, 2021The safety and well-being of the people who use our products is our number one priority. We are aware of an extremely rare disorder involving people with blood clots in combination with low platelets in a small number of individuals who have received our COVID-19 vaccine. The United States Centers for Disease Control (CDC) and Food and Drug Administration (FDA) are reviewing data involving six reported U.S. cases out of more than 6.8 million doses administered. Out of an abundance of caution, the CDC and FDA have recommended a pause in the use of our vaccine.

In addition, we have been reviewing these cases with European health authorities. We have made the decision to proactively delay the rollout of our vaccine in Europe.

We have been working closely with medical experts and health authorities, and we strongly support the open communication of this information to healthcare professionals and the public.

The CDC and FDA have made information available about proper recognition and management due to the unique treatment required with this type of blood clot. The health authorities advise that people who have received our COVID-19 vaccine and develop severe headache, abdominal pain, leg pain, or shortness of breath within three weeks after vaccination should contact their health care provider.

For more information on the Janssen COVID-19 vaccine, click here.

SOURCE

https://endpts.com/us-pauses-jj-vaccinations-amid-new-reports-of-rare-serious-blood-clots/

Thrombotic Thrombocytopenia after ChAdOx1 nCov-19 Vaccination, AstraZeneca

Several cases of unusual thrombotic events and thrombocytopenia have developed after vaccination with the recombinant adenoviral vector encoding the spike protein antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (ChAdOx1 nCov-19, AstraZeneca).

This study found that vaccination with ChAdOx1 nCov-19 can result in the rare development of immune thrombotic thrombocytopenia mediated by platelet-activating antibodies against PF4, which clinically mimics autoimmune heparin-induced thrombocytopenia (aHIT).

This study also found that the addition of immune globulin in doses that are readily achieved clinically was effective in inhibiting platelet activation by patients’ antibodies.

Clinician reluctance to start anticoagulation may be tempered by administering high-dose intravenous immune globulin to raise the platelet count, especially when a patient presents with severe thrombocytopenia and thrombosis, such as cerebral venous thrombosis.

Given the parallels with autoimmune heparininduced thrombocytopenia, anticoagulant options should include nonheparin anticoagulants used for the management of heparin-induced thrombocytopenia, unless a functional test has excluded heparin-dependent enhancement of platelet activation.

Finally, this paper suggest naming this novel entity vaccine-induced immune thrombotic thrombocytopenia (VITT) to avoid confusion with heparin-induced thrombocytopenia.

SOURCE

From: “Prof. Marcus W Feldman” <mfeldman@stanford.edu>

Date: Monday, April 12, 2021 at 1:10 PM

To: “Aviva Lev-Ari, PhD, RN” <AvivaLev-Ari@alum.berkeley.edu>

Subject: Fwd: Vaccination thrombotic events clinically mimics Heparin-induced thrombocytopenia | CD8+ Memory T Cell Responses against Viral Variants

Thrombotic Thrombocytopenia after ChAdOx1 nCov-19 Vaccination

This article was published on April 9, 2021, at NEJM.org. DOI: 10.1056/NEJMoa2104840

BACKGROUND Several cases of unusual thrombotic events and thrombocytopenia have developed after vaccination with the recombinant adenoviral vector encoding the spike protein antigen of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (ChAdOx1 nCov-19, AstraZeneca). More data were needed on the pathogenesis of this unusual clotting disorder. METHODS We assessed the clinical and laboratory features of 11 patients in Germany and Austria in whom thrombosis or thrombocytopenia had developed after vaccination with ChAdOx1 nCov-19. We used a standard enzyme-linked immunosorbent assay to detect platelet factor 4 (PF4)–heparin antibodies and a modified (PF4-enhanced) platelet-activation test to detect platelet-activating antibodies under various reaction conditions. Included in this testing were samples from patients who had blood samples referred for investigation of vaccine-associated thrombotic events, with 28 testing positive on a screening PF4–heparin immunoassay. RESULTS Of the 11 original patients, 9 were women, with a median age of 36 years (range, 22 to 49). Beginning 5 to 16 days after vaccination, the patients presented with one or more thrombotic events, with the exception of 1 patient, who presented with fatal intracranial hemorrhage. Of the patients with one or more thrombotic events, 9 had cerebral venous thrombosis, 3 had splanchnic-vein thrombosis, 3 had pulmonary embolism, and 4 had other thromboses; of these patients, 6 died. Five patients had disseminated intravascular coagulation. None of the patients had received heparin before symptom onset. All 28 patients who tested positive for antibodies against PF4–heparin tested positive on the platelet-activation assay in the presence of PF4 independent of heparin. Platelet activation was inhibited by high levels of heparin, Fc receptor–blocking monoclonal antibody, and immune globulin (10 mg per milliliter). Additional studies with PF4 or PF4–heparin affinity purified antibodies in 2 patients confirmed PF4-dependent platelet activation. CONCLUSIONS Vaccination with ChAdOx1 nCov-19 can result in the rare development of immune thrombotic thrombocytopenia mediated by platelet-activating antibodies against PF4, which clinically mimics autoimmune heparin-induced thrombocytopenia. (Funded by the German Research Foundation.)

SOURCE

Thrombotic Thrombocytopenia after ChAdOx1 nCov-19 Vaccination

Andreas Greinacher, M.D., Thomas Thiele, M.D., Theodore E. Warkentin, M.D., Karin Weisser, Ph.D., Paul A. Kyrle, M.D., and Sabine Eichinger, M.D.

Author Affiliations

From Institut für Immunologie und Transfusionsmedizin, Universitätsmedizin Greifswald, Greifswald (A.G., T.T.), and the Division of Safety of Medicinal Products and Medical Devices, Paul-Ehrlich-Institut (Federal Institute for Vaccines and Biomedicines), Langen (K.W.) — both in Germany; the Departments of Pathology and Molecular Medicine and of Medicine, McMaster University, Hamilton, ON, Canada (T.E.W.); and the Department of Medicine I, Division of Hematology and Hemostaseology, Medical University of Vienna, Vienna (P.A.K., S.E.).

Address reprint requests to Dr. Greinacher at Institut für Immunologie und Transfusionsmedizin, Abteilung Transfusionsmedizin, Sauerbruchstrasse, 17487 Greifswald, Germany.

NEJM.org. DOI: 10.1056/NEJMoa2104840

https://files.constantcontact.com/6edd32c5501/a5408883-7fbd-4509-b11d-8d52c6b807fc.pdf

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Cryo-EM disclosed how the D614G mutation changes SARS-CoV-2 spike protein structure.

Reporter: Dr. Premalata Pati, Ph.D., Postdoc

SARS-CoV-2, the virus that causes COVID-19, has had a major impact on human health globally; infecting a massive quantity of people around 136,046,262 (John Hopkins University); causing severe disease and associated long-term health sequelae; resulting in death and excess mortality, especially among older and prone populations; altering routine healthcare services; disruptions to travel, trade, education, and many other societal functions; and more broadly having a negative impact on peoples physical and mental health.

It’s need of the hour to answer the questions like what allows the variants of SARS-CoV-2 first detected in the UK, South Africa, and Brazil to spread so quickly? How can current COVID-19 vaccines better protect against them?

Scientists from the Harvard Medical School and the Boston Children’s Hospital help answer these urgent questions. The team reports its findings in the journal “Science a paper entitled Structural impact on SARS-CoV-2 spike protein by D614G substitution. The mutation rate of the SARS-CoV-2 virus has rapidly evolved over the past few months, especially at the Spike (S) protein region of the virus, where the maximum number of mutations have been observed by the virologists.

Bing Chen, HMS professor of pediatrics at Boston Children’s, and colleagues analyzed the changes in the structure of the spike proteins with the genetic change by D614G mutation by all three variants. Hence they assessed the structure of the coronavirus spike protein down to the atomic level and revealed the reason for the quick spreading of these variants.


This model shows the structure of the spike protein in its closed configuration, in its original D614 form (left) and its mutant form (G614). In the mutant spike protein, the 630 loop (in red) stabilizes the spike, preventing it from flipping open prematurely and rendering SARS-CoV-2 more infectious.

Fig. 1. Cryo-EM structures of the full-length SARS-CoV-2 S protein carrying G614.

(A) Three structures of the G614 S trimer, representing a closed, three RBD-down conformation, an RBD-intermediate conformation and a one RBD-up conformation, were modeled based on corresponding cryo-EM density maps at 3.1-3.5Å resolution. Three protomers (a, b, c) are colored in red, blue and green, respectively. RBD locations are indicated. (B) Top views of superposition of three structures of the G614 S in (A) in ribbon representation with the structure of the prefusion trimer of the D614 S (PDB ID: 6XR8), shown in yellow. NTD and RBD of each protomer are indicated. Side views of the superposition are shown in fig. S8.

IMAGE SOURCE: Bing Chen, Ph.D., Boston Children’s Hospital, https://science.sciencemag.org/content/early/2021/03/16/science.abf2303

The work

The mutant spikes were imaged by Cryo-Electron microscopy (cryo-EM), which has resolution down to the atomic level. They found that the D614G mutation (substitution of in a single amino acid “letter” in the genetic code for the spike protein) makes the spike more stable as compared with the original SARS-CoV-2 virus. As a result, more functional spikes are available to bind to our cells’ ACE2 receptors, making the virus more contagious.


Fig. 2. Cryo-EM revealed how the D614G mutation changes SARS-CoV-2 spike protein structure.

IMAGE SOURCE:  Zhang J, et al., Science

Say the original virus has 100 spikes,” Chen explained. “Because of the shape instability, you may have just 50 percent of them functional. In the G614 variants, you may have 90 percent that is functional. So even though they don’t bind as well, the chances are greater and you will have an infection

Forthcoming directions by Bing Chen and Team

The findings suggest the current approved COVID-19 vaccines and any vaccines in the works should include the genetic code for this mutation. Chen has quoted:

Since most of the vaccines so far—including the Moderna, Pfizer–BioNTech, Johnson & Johnson, and AstraZeneca vaccines are based on the original spike protein, adding the D614G mutation could make the vaccines better able to elicit protective neutralizing antibodies against the viral variants

Chen proposes that redesigned vaccines incorporate the code for this mutant spike protein. He believes the more stable spike shape should make any vaccine based on the spike more likely to elicit protective antibodies. Chen also has his sights set on therapeutics. He and his colleagues are further applying structural biology to better understand how SARS-CoV-2 binds to the ACE2 receptor. That could point the way to drugs that would block the virus from gaining entry to our cells.

In January, the team showed that a structurally engineered “decoy” ACE2 protein binds to SARS-CoV-2 200 times more strongly than the body’s own ACE2. The decoy potently inhibited the virus in cell culture, suggesting it could be an anti-COVID-19 treatment. Chen is now working to advance this research into animal models.

Main Source:

Abstract

Substitution for aspartic acid by glycine at position 614 in the spike (S) protein of severe acute respiratory syndrome coronavirus 2 appears to facilitate rapid viral spread. The G614 strain and its recent variants are now the dominant circulating forms. We report here cryo-EM structures of a full-length G614 S trimer, which adopts three distinct prefusion conformations differing primarily by the position of one receptor-binding domain. A loop disordered in the D614 S trimer wedges between domains within a protomer in the G614 spike. This added interaction appears to prevent premature dissociation of the G614 trimer, effectively increasing the number of functional spikes and enhancing infectivity, and to modulate structural rearrangements for membrane fusion. These findings extend our understanding of viral entry and suggest an improved immunogen for vaccine development.

https://science.sciencemag.org/content/early/2021/03/16/science.abf2303?rss=1

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Glycosylation and its Role in SARS-CoV-2 Viral Pathogenesis

Author: Meg Baker, PhD

 

N-Glycosylation and COVID19

Glycobiology

N-linked glycosylation (NLG) is a complex biosynthetic process that regulates proper folding of proteins through and intracellular transport of proteins to the secretory pathway. This co- and post-translational modification occurs by a series of enzymatic reactions, which results in the transfer of a core glycan from the lipid carrier to a protein substrate and the possibility for further remodeling of the glycan. The enzymes are located in the cytosolic and the luminal side of the ER membrane. The study of NLG and related effects of glycans is called glycobiology.

NLG takes place at sites specified in the protein sequence itself. N-linked oligosaccharides are attached via a GlcNAc linked to the side chain nitrogen of Asn found in the consensus sequence NXT/S (X ≠ P) known as the ‘glycosylation sequon’. Formation of a precursor branched carbohydrate chain, the lipid-linked oligosaccharide (LLO) structure, takes place in the endoplasmic reticulum. The LLO consists of a Glc3Man9GlcNAc2 molecule (three glucose, nine mannose, and two N-acetylglucosamine sugars) linked to a dolichol pyrophosphate. The enzyme oligosaccharyltransferase then moves it to an Asn in the polypeptide.

The removal of the three glucose sugars from the new N-linked glycan signals that the structure is ready for transport to the Golgi where mannose is removed yielding a carbohydrate chain containing five–nine mannose sugars. Further removal of mannose residues can lead to the core structure containing three mannose and two N-acetylglucosamine residues, which may then be elongated with a variety of different monosaccharides including galactose, N-acetylglucosamine (aka NAG or GlcNac), N-acetylgalactosamine, fucose, and sialic acid, many of which can also exist in sulfated form.

The enzymes involved in this essential process are evolutionarily conserved. However, the genes and their specific functions, have evolved uniquely for each selected organism. Therefore, each organism and each individual cell, depending on genetic background and influenced by nutritional and such things as disease status, will decorate secreted proteins in a unique manner.

The advent of biologic medicines (protein based therapeutics) presents the challenge of making sure that the primary protein sequence is specified but also that the manufacture of the protein – typically in a eukaryotic cell host capable of glycosylation – will take place with some degree of reproducibility. The large number of monoclonal antibody therapeutics absolutely require glycosylation for proper structural integrity but are generally made in rodent or other nonhuman cells. Thus, the term “biosimilar” rather than generic is the term being used to connote the variation which will necessarily result due to different manufacturing process even of the same genetic sequence.

 

Viral Glycoproteins

It should be obvious that the viral genome is not large enough to encompass the collection of enzymes required for glycosylation of any type and viral glycoproteins are formed by the host cell in which the virus is replicating. The study of the impact of glycan content and composition on viral infectivity and, more importantly, vaccine development is a subject which has been late to be addressed largely due to the technical difficulty and lack of methods for analyzing protein glycan composition. However, progress is being made. Raska et al. (J Biol Chem 2010 Jul 2; 285(27): 20860–20869. Glycosylation Patterns of HIV-1 gp120 Depend on the Type of Expressing Cells and Affect Antibody Recognition)  was able to perform such an analysis on the HIV-1 virus albeit almost 30 years after its emergence in human populations. The findings of this study may explain, in part, the difficulty in developing a vaccine against HIV.

 

SARS-CoV-2 spike protein (P0DTC2 uniprot.org) – as so popularly depicted – is a trimer poking out of the lipid coat that protects it’s genome. The spike protein, like gp120 in HIV, is the point of contact with the human cell ACE2 receptor it uses to gain entry. The spike protein contains two functional external subunits, designated S1 and S2. S1 separated by a furin cleavage site from S2, forms the apex of the trimeric spike structure, is responsible for attachment to the ACE2 receptor. S2 is responsible for fusion to the cell membrane. (PDB: 6VSB shows a 3D image of the protein structure, including glycan positions). There are 22 glycans per polypeptide or 66 per spike trimer protein (Watanabe et al. 2021 Site-specific glycan analysis of the SARS-CoV-2 spike. Science 17 Jul 2020:Vol. 369, Issue 6501, pp. 330-333 ).

Although shielding of receptor binding sites by glycans is a common feature of viral glycoproteins, Watanabe (ibid) note the low mutation rate of SARS-CoV-2 and that as yet, there have been no observed mutations to N-linked glycosylation sites.

The development of a vaccine or individual antibodies or antibody cocktails with neutralizing (viral entry blocking or virocidal activity) is also influenced by the presence or absence of glycans and how well they target the natural conformation of the spike protein. Papageorgiou et al. The SARS-CoV-2 Spike Glycoprotein as a Drug and Vaccine Target: Structural Insights into Its Complexes with ACE2 and Antibodies. Cells 2020 Oct 22;9(11):2343. doi: 10.3390/cells9112343. SARS-CoV-2 Spike – Stanford Coronavirus Antiviral Research Database It should be noted that the mRNA vaccines (or other nucleic acid formats) may obviate these analysis because the immune response is to a spike protein made and glycosylated in the human host’s own body and therefore will be customized to each individual in some sense.

Glycans may themselves represent drug targets. Casolino et al. suggest an essential structural role of N-glycans at sites N165 and N234 in modulating the conformational dynamics of the spike’s receptor binding domain (RBD), which is responsible for ACE2 recognition (Casolino et al. 2020. Beyond Shielding: The Roles of Glycans in the SARS-CoV-2 Spike Protein ACS Cent Sci. 2020 Oct 28; 6(10): 1722–1734),

 

COVID19 Variants

SARS-CoV-2 lineage B.1.1.7 likely arose in the United Kingdom in September 2019 and is characterized by 17 mutations, including 8 in the spike protein (Rambaut et al., 2020). Other lineages, including B.1.351, initially detected in South Africa (Tegally et al., 2020), and most recently lineage P.1, first documented in the Amazonia region of Brazil (Faria et al., 2020), carry additional mutations. All three lineages are characterised by a N501Y (Asn to Tyr) mutation in the spike protein, while both B.1.351 and P.1 also carry the spike mutation E484K. In addition, both B.1.1.7 and B.1.351, but not P.1, have acquired short sequence deletions in the spike protein. N501Y is in the receptor-binding domain (RBD) but is not a glycosylation site.

Reference

See the CDC Emerging SARS-CoV-2 Variants | CDC

 

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Need for Global Response to SARS-CoV-2 Viral Variants

Reporter: Aviva Lev-Ari, PhD, RN

NIH experts discuss SARS-CoV-2 viral variants

Editorial emphasizes need for global response.

 

The rise of several significant variants of SARS-CoV-2, the virus that causes COVID-19, has attracted the attention of health and science experts worldwide. In an editorial published today in JAMA: The Journal of the American Medical Association, experts from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, outline how these variants have arisen, concerns about whether vaccines currently authorized for use will continue to protect against new variants, and the need for a global approach to fighting SARS-CoV-2 as it spreads and acquires additional mutations.

The article was written by NIAID Director Anthony S. Fauci, M.D.; John R. Mascola, M.D., director of NIAID’s Vaccine Research Center (VRC); and Barney S. Graham, M.D., Ph.D., deputy director of NIAID’s VRC.

The authors note that the overlapping discovery of several SARS-CoV-2 variants has led to confusing terms used to name them. The appearance of SARS-CoV-2 variants is so recent that the World Health Organization and other groups are still developing appropriate nomenclature for the different variants.

Numerous SARS-CoV-2 variants have emerged over the last several months. The authors note that the variants known as B.1.1.7 (first identified in the United Kingdom) and B.1.351 (first identified in South Africa) concern scientists because of emerging data suggesting their increased transmissibility.

Variants can carry several different mutations, but changes in the spike protein of the virus, used to enter cells and infect them, are especially concerning. Changes to this protein may cause a vaccine to be less effective against a particular variant. The authors note that the B.1.351 variant may be partially or fully resistant to certain SARS-CoV-2 monoclonal antibodies currently authorized for use as therapeutics in the United States.

The recognition of all new variants, including a novel emergent strain (20C/S:452R) in California, requires systematic evaluation, according to the authors. The rise of these variants is a reminder that as long as SARS-CoV-2 continues to spread, it has the potential to evolve into new variants, the authors stress. Therefore, the fight against SARS-CoV-2 and COVID-19 will require robust surveillance, tracking, and vaccine deployment worldwide.

The authors also note the need for a pan-coronavirus vaccine. Once researchers know more about how the virus changes as it spreads, it may be possible to develop a vaccine that protects against most or all variants. While similar research programs are already in place for other diseases, such as influenza, the changing nature of SARS-CoV-2 indicates that they will be necessary for this virus.

SOURCE

https://www.nih.gov/news-events/news-releases/nih-experts-discuss-sars-cov-2-viral-variants

 

Editorial
February 11, 2021

SARS-CoV-2 Viral Variants—Tackling a Moving Target

JAMAPublished online February 11, 2021. doi:10.1001/jama.2021.2088

In this issue of JAMA, Zhang and colleagues1 report the emergence of a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant in Southern California that accounted for 44% (37 of 85) of samples collected and studied in January 2021. The terminology of viral variation can be confusing because the media and even scientific communications often use the terms variantstrain, and lineage interchangeably. The terminology reflects the basic replication biology of RNA viruses that results in the introduction of mutations throughout the viral genome. When specific mutations, or sets of mutations, are selected through numerous rounds of viral replication, a new variant can emerge. If the sequence variation produces a virus with distinctly different phenotypic characteristics, the variant is co-termed a strain. When through genetic sequencing and phylogenetic analysis a new variant is detected as a distinct branch on a phylogenetic tree, a new lineage is born.

New variants become predominant through a process of evolutionary selection that is not well understood. Once identified, several questions arise regarding the potential clinical consequences of a new variant: Is it more readily transmitted; is it more virulent or pathogenic; and can it evade immunity induced by vaccination or prior infection? For these reasons, new viral variants are studied, leading to the terms variant under investigation or variant of concern.

To communicate effectively about new SARS-CoV-2 variants, a common nomenclature is needed, which like the virus, is evolving. Fortunately, the World Health Organization (WHO) is working on a systematic nomenclature that does not require a geographic reference, since viral variants can spread rapidly and globally. Currently, the terminology is overlapping, as reflected in the report by Zhang et al.1 This new variant (CAL.20C) is termed lineage 20C/S:452R in Nextstrain nomenclature,2 referring to the parent clade 20C and spike alteration 452R. Similarly, using a distinct PANGO nomenclature,3 this variant derives from lineage B (B.1.429 and B.1.427). While alterations in any viral genes can have implications for pathogenesis, those arising in the spike protein that mediates viral entry into host cells and is a key target of vaccines and monoclonal antibodies are of particular interest. The new variant, identified in California and termed 20C/S:452R, has 3 amino acid changes in the spike protein, represented using the single-letter amino acid nomenclature: S13I, W152C, and L452R. To interpret this new set of alterations, it is useful to review what is known about recent variants that have become predominant in other regions of the world.

During the early phase of the SARS-CoV-2 pandemic, there were only modest levels of genetic evolution; however, more recent information indicates that even a single amino acid substitution can have biological implications. Starting in April 2020, the original SARS-CoV-2 strain was replaced in many regions of the world by a variant called D614G, which was subsequently shown to increase the efficiency of viral replication in humans and was more transmissible in animal models.46 The D614G strain appears to position its receptor binding domain to interact more efficiently with the ACE2 receptor, and it is associated with higher nasopharyngeal viral RNA loads, which may explain its rise to dominance.

In October 2020, sequencing analysis in the UK detected an emerging variant, later termed B.1.1.7 or 20I/501Y.V1, which is now present and rapidly spreading in many countries.7 B.1.1.7 contains 8 mutations in the spike protein and maintains the D614G mutation. One of these, N501Y, appears to further increase the spike protein interaction with the ACE2 receptor. Epidemiological studies indicate that the B.1.1.7/20I/501Y.V1 strain is 30% to 80% more effectively transmitted and results in higher nasopharyngeal viral loads than the wild-type strain of SARS-CoV. Also of concern are retrospective observational studies suggesting an approximately 30% increased risk of death associated with this variant.8

Another notable variant, 20H/501Y.V2 or B.1.351, was first identified is South Africa, where it has rapidly become the predominant strain.9 Cases attributed to this strain have been detected in multiple countries outside of South Africa, including recent cases in the US. B.1.351 shares the D614G and N501Y mutations with B.1.1.1.7; thus, it is thought to also have a high potential for transmission. There are no data yet to suggest an increased risk of death due to this variant. Importantly, this constellation of mutations—9 total in the spike protein—add yet another dimension of concern. B.1.351 strains are less effectively neutralized by convalescent plasma from patients with coronavirus disease 2019 (COVID-19) and by sera from those vaccinated with several vaccines in development.1012 The decrement in neutralization can be more than 10-fold with convalescent plasma and averages 5- to 6-fold less with sera from vaccinated individuals. Fortunately, neutralization titers induced by vaccination are high, and even with a 6-fold decrease, serum can still effectively neutralize the virus.

Nonetheless, these data are concerning because they indicate that viral variation can result in antigenic changes that alter antibody-mediated immunity. This is highlighted by in vitro studies showing the B.1.351 strain to be partially or fully resistant to neutralization by certain monoclonal antibodies, including some authorized for therapeutic use in the US.12 The prevalent strains in the US appear to remain sensitive to therapeutic monoclonal antibodies; however, recent evolutionary history raises the concern that the virus could be only a few mutations away from more substantive resistance.

COVID-19 vaccine development has been an extraordinary success; however, it is unclear how effective these vaccines will be against the new variants. The interim data from 2 randomized placebo-controlled vaccine studies, the rAd26 from Janssen and a recombinant protein from Novavax, offer some insight. The Janssen study included sites in the US, Brazil, and South Africa with efficacy against COVID-19 at 72%, 66%, and 57%, respectively.13 Novavax reported efficacy from studies in the UK and South Africa with overall efficacy of 89% and 60%, respectively.14 Viral sequence data from infected patients showed that the B.1.351 strain was responsible for the majority of infections in South Africa. Lower vaccine efficacy in the South Africa cohort could be related to antigenic variation or to geographic or population differences. Despite the reduced efficacy, the rAd26 vaccine was 85% effective overall in preventing severe COVID-19, and protection was similar in all regions.

These data suggest that current vaccines could retain the ability to prevent hospitalizations and deaths, even in the face of decreased overall efficacy due to antigenic variation. It is unclear whether changes in vaccine composition will be needed to effectively control the COVID-19 pandemic; however, it is prudent to be prepared. Some companies have indicated plans to manufacture and test vaccines based on emerging variants, and such studies will provide important information on the potential to broaden the immune response.

The recognition of a novel emergent variant, 20C/S:452R, in the most populous US state necessitates further investigation for implications of enhanced transmission. In particular, the L452R mutation in the spike protein could affect the binding of certain therapeutic monoclonal antibodies. The emergence of this and other new variants is likely to be a common occurrence until the spread of this virus is reduced. This emphasizes the importance of a global approach to surveillance, tracking, and vaccine deployment. The approach should be systematic and include in vitro assessment of sensitivity to neutralization by monoclonal antibodies and vaccinee sera, vaccine protection of animals against challenge with new strains, and field data defining viral sequences from breakthrough infections in vaccinees. The infrastructure and process used for tracking and updating influenza vaccines could be used to inform that process. Finally, SARS-CoV-2 will be with the global population for some time and has clearly shown its tendency toward rapid antigenic variation, providing a “wake-up call” that a sustained effort to develop a pan-SARS-CoV-2 vaccine is warranted.

SOURCE

https://jamanetwork.com/journals/jama/fullarticle/2776542

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