Early immune predictors of sustained SARS-CoV-2 antibody responses after COVID-19 disease

COVID-19, a disease caused by a new Coronavirus, is an unprecedented global health crisis for which we currently have nor safe nor rapid response. Given the absence of vaccines and effective therapies, it is essential to understand the development, effectiveness and maintenance of antiviral responses against its causing agent, the SARS-CoV-2 virus. The highly variable immune response against SARS-CoV-2 define the severity of the disease, but many critical questions remain: 1) can we predict patients that will experience a severe disease and delayed viral clearance? 2) do survivors of COVID-19 develop durable and protective antiviral immunity? 3) can serology identify convalescent COVID-19 patients who are at high risk of re-infection? 4) does re-exposure to the virus boost their antiviral immunity? We propose the creation of a multi-site consortium composed of 12 scientists (6 women and 6 men) with solid expertise in virology and immunology and from leading academic institutions in Quebec (UdeM, IRCM) and the US (Columbia, NY) to study antiviral immunity in COVID-19 in both sexes to address unresolved issues, as outlined in the CIHR call: in Aim 1 and 2, we focus on early clinical and immunological features of COVID-19 that can predict the emergence of protective and durable antibodies. We will compare cohorts of patients enrolled in the "Biobanque quebecoise de la COVID-19" (BQC19) that experienced mild or severe COVID-19 or COVID-19-like symptoms attributed to another infectious agent. In Aim 3, we will focus on a cohort of health care worker tending COVID-19 patients, therefore at higher risk of repeat exposure to the virus. Using this cohort, we will study the effect of repeat exposure on immunity boosting against the virus and help define the immunological requirements of a successful vaccine. Taken together, our proposal will provide the immunological perspective needed to better prepare and implement a safe exit from the current public health crisis.