Immune Responses to COVID-19 (SARS-CoV-2 Related Infection); Isolation of Human Neutralizing Monoclonal Antibodies for Therapeutics and Vaccine Design Approaches: a Prospective Monocentric Trial With Collaborative Sample Collection.

A RELIRE PAR PASCAL POIGNARD

1. CURRENT KNOWLEDGE ABOUT THE PATHOLOGY

Coronaviruses are a large family whose members share a tropism for epitheliums. They are usually responsible of ordinary and frequent infections in humans, with acute and limited inflammation of the respiratory tract. The fact that they are RNA viruses (which confers them an important plasticity), and that some types infect animals and others infect human, explain that they may be a source of new human diseases arising from animal strains. This is how two Coronavirus outbreaks spreading in several countries emerged in the past years: The Severe Acute Respiratory Syndrome (SARS), in 2003; and the Middle East Respiratory Syndrome (MERS) in 2012. In January 2020, another coronavirus outbreak has been described: the COVID-19 outbreak, related to the SARS-CoV-2.

The disease mentioned as coronavirus disease 2019 (COVID-19) has been detected for the first time in China in December 2019; a first case cluster was strongly related to a live-animal market, suggesting an animal origin; the following descriptions did clearly established a human-to-human transmission, with a reproduction number (R0) between 2.5 and 3.5. Some scientific publications described potential contaminations by asymptomatic subjects. While China finally managed to record a great decrease in the number of daily cases (82,241 total cases with 3,309 deaths on the 31st March 2020), the epidemic rapidly reached many other countries. In France, several sites of active virus circulation (l'Oise, Mulhouse, la Haute-Savoie) finally led to an important development of the epidemic in France (44,450 cases with 3,024 deaths on March 31st 2020).

The disease consists in a pneumonia reminding of the Acute Respiratory Distress Syndrome (ARDS) in several aspects; after a 5 days median incubation time, symptoms develops with cough which can be febrile/feverish, and which can evolve/develop towards dyspnea, and in some instance towards ARDS after 7 to 10 days of evolution. If the first epidemiological descriptions stated a high proportion of severe cases (more than 33%), a study including more than 70,000 cases then suggested that 15% cases were severe/marked, and 5% critical; however, it is likely that asymptomatic or little symptomatic cases can be numerous, according to new studies. To date, no curative antiviral treatment demonstrated clinical efficacy but many clinical trials are ongoing. This disease is a problem for the healthcare system for two reasons: its contagiousness (which require major social distancing measures) and its morbidity (which paralyze the healthcare system by requiring too much ICU hospitalization). 2. IMMUNE RESPONSES IN COVID-19 STATE OF ART: