Leaders in Pharmaceutical Business Intelligence (LPBI) Group

María Magdalena Aguirre García

Javier Mancilla-Galindo

Mercedes Paredes-Paredes

Álvaro Zamudio Tiburcio

Nydia Ávila-Vanzzini

Human coronaviruses (HCoVs) were first isolated from patients with the common cold in the 1960s [1–3]. Seven HCoVs known to cause disease in humans have since been identified: HCoV-229E, HCoV-NL63, HCoV-OC43, HCoV-HKU1, the SARS coronavirus (SARS-CoV), the Middle East respiratory syndrome coronavirus and the novel SARS-CoV-2 [4]. The latter was identified after a spike in cases of pneumonia of unknown etiology in Wuhan, Hubei Province, China during December 2019 and was initially named novel coronavirus (2019-nCoV) [5,6]. The virus was renamed SARS-CoV-2 according to the International Committee on Taxonomy of Viruses classification criteria due to its genomic closeness to SARS-CoV; the disease caused by this virus was named coronavirus disease (COVID-19) according to the WHO criteria for naming emerging diseases [7]. SARS-CoV-2 belongs to the genera Betacoronavirus and shares a different degree of genomic similarity with the other two epidemic coronaviruses: SARS-CoV (∼79%) and Middle East respiratory syndrome coronavirus (∼50%) [8].

COVID-19 has caused considerable morbidity and mortality worldwide and has become the central phenomenon that is shaping our current societies. Human-to-human transmission is the main route of spread of the virus, mainly through direct contact, respiratory droplets and aerosols [9–12]. Management of COVID-19 has been extremely challenging due to its high infectivity, lack of effective therapeutics and potentially small groups of individuals (i.e., asymptomatic or mild disease) rapidly spreading the disease [13–17]. Although research describing COVID-19 and the mechanisms of infection by SARS-CoV-2 and its pathogenesis has expanded rapidly, there is still much to be learnt. Important gaps in knowledge which remain to be elucidated are the dynamic and complex interactions between the virus and the host’s immune system, as well as the potential interspecies communications occurring between ecological niches encompassing distinct microorganisms in both healthy individuals and persons living with chronic diseases, and how these interactions could determine or modulate disease progression and outcomes.

In this review, we describe recent insights into these topics, as well as remaining questions whose answers will allow us to understand how interactions between the virus, the immune system and microbial components could possibly be related to disease states in patients with COVID-19, as well as existing studies of the microbiome in patients with COVID-19.