Grant: Project Grant

The pace of development of effective SARS-CoV-2 vaccines and their deployment have been truly remarkable, and unprecedented in the history of infectious diseases. However, many expert epidemiologists expect that SARS-CoV-2 will become endemic worldwide, this at significant residual levels. The Canadian population is expected to become soon in majority vaccinated against this virus, and/or have experienced prior infection. While vaccine protection is very good it is not perfect, its durability not yet established, and as an RNA virus, SARS-CoV-2 is prone to mutations that can lead to escape from immune responses. Furthermore, some populations with chronic medical conditions are expected to remain at risk to develop an infection severe enough to require hospitalization. Here, we propose to identify viral, immune and host factors associated with severe COVID-19 in patients that have been previously vaccinated against SARS-CoV-2, previously infected, or both. This proposal will compare immune responses generated by immunocompromised patients, healthcare workers and convalescent people previously hospitalized because of COVID-19 in the contexts of vaccination and (re)infection. This works will help identify people at higher risks of severe re-infection and adopt adequate prophylactic and therapeutic measures to mitigate the risk.