Project 466199

Throughout the course of the COVID-19 pandemic in Canada, infection and transmission among children has progressively increased, due to more transmissible SARS-CoV-2 variants and relatively low rates of pediatric vaccination.1 COVID-19 vaccines are currently approved for use in children 5 years and older in Canada. However, as of May 2022, only 42% of 5 to 11- and 84% of 12 to 17-year-olds have received a second dose. Although the initial Omicron wave has receded, transmission of the BA.2 and newer variants continues. Despite estimated large numbers of pediatric COVID-19, increasing hospitalization numbers, and the Multisystem Inflammatory Syndrome in Children (MIS-C), children predominantly have mild or asymptomatic SARS-CoV-2 infection.2,3 This, combined with the fact that routine COVID-19 laboratory testing for outpatients in most parts of the country is no longer available means that rates of infection are largely under measured in the absence of serologic testing, in which antibodies to the virus are used to detect past infection and/or vaccination. Relatively few Canadian serology studies have included children, and these may not be nationally representative. Furthermore, because levels of transmission, vaccination and immunity are continually changing, ongoing surveillance is needed. This proposal responds to the Pediatric Outcomes imProvement through COordination of Research Networks (POPCORN) Supplement funding opportunity posted on May 27 (and due May 31) with the overall goal of obtaining broad COVID-19 serosurvey data among Canadian children, by leveraging POPCORN’s infrastructure. POPCORN is a new CIHR-funded research platform that unifies multiple pediatric research networks and investigative teams at 16 sites across Canada, to study questions of child health importance, starting with COVID-19. The POPCORN structure involves a Coordinating Centre (housed within the Maternal Infant Child Youth Research Network, MICYRN), Content Expertise Pillars (including Infectious Diseases and Emergency Medicine), and Cross-cutting Pillars (Epidemiology & Biostatistics, Data Governance, Biobanking, EDI, Patient engagement, and Knowledge Mobilization). The platform is well positioned to rapidly implement a serosurvey study given its master contract agreement across member sites and allows the addition of new studies to the platform without undue contractual delays. More accurate and current data about COVID-19 infection and immunity in children have the potential to help predict future pandemic trends in children and among the general population, inform ongoing estimates of the relative severity of infection in children (by comparing rates of infection and hospitalization), the possible role of children in community transmission, the impact of instituting or relaxing preventive public health measures aimed at children, and population-level immunity and need for additional vaccination.