Grant: CIHR-CEPI Leadership Award for Vaccine Research

As of July 2021, four COVID-19 vaccines are available in Canada. Approval of new vaccines will require a better understanding of how COVID-19 vaccines work and protect against infection. Our overall objective is to compare (i) antibody responses to these 4 COVID-19 vaccines and (ii) peoples' immune responses after vaccination or natural infection by the SARS-CoV-2 virus. Natural infection is usually considered the 'best' immune response to protect against future infection. We will recruit child and adult volunteers in two groups: those who were vaccinated (total 400 people) and those who had COVID-19 (total 158 people). For those who were vaccinated, we will collect blood samples in before and after vaccination. In those who were infected, we will collect samples up to 12 months after infection. We will also collect information to see if there are other factors (eg, age, sex, gender, other health issues) that affect the person's responses. We will measure responses after vaccination and infection by analysis of how much antibody there is and what the antibody is doing, and of changes in genes that are switched 'on' or 'off'. To analyze the data, we will use sophisticated methods we developed and used to understand how hepatitis B virus vaccines work. We predict to be able to identify similarities and differences, at a molecular level, in immune responses among the different vaccines and between vaccination and natural infection. These head-to-head comparisons will help us to make more effective vaccines in Canada and around the world.