Large study measures COVID in children and teens

MONTREAL – In Canada, the vast majority of COVID-19 cases in the 0 to 18 age group have been mild or asymptomatic. This fact, combined with the reduction in routine COVID-19 laboratory testing across most of the country, means that the infection rates in children and adolescents are largely unknown. What’s more, since levels of transmission, vaccination and immunity are continually changing, ongoing surveillance is necessary to help guide public health policy.

To address the knowledge gap, the Government of Canada and the Canadian Institutes of Health Research (CIHR), through the COVID-19 Immunity Task Force (CITF), are providing $2.6 million to conduct the largest serosurvey of children and youth to date in Canada for SARS-CoV-2. The study, which benefits from the network established for an existing CIHR-funded project called Pediatric Outcomes Improvement through Coordination of Research Networks (POPCORN), is called COVID-19 seroepidemiology among children Using Retrieved POPCORN Site Leftover blood Samples (CURNLS).

It is led by Drs. Soren Gantt and Caroline Quach-Thanh (pictured), investigators at CHU Sainte-Justine Research Centre and professors at the Université de Montréal. POPCORN is also led by Dr. Quach-Thanh and brings together pediatric health researchers from 16 hospital research sites across Canada to monitor COVID-19 infections, vaccination, and social impacts among children and youth.

“The CURNLS study involves testing existing blood samples from patients aged 0 to 18 who visit hospital emergency departments across Canada with the goal of identifying whether they’ve had COVID-19 and whether they have immunity from infection or vaccination,” says Dr. Gantt. “We will combine this information with rates of transmission, hospitalization, vaccination, and use of public health measures to inform public health policy.”

“By including large numbers of children from the POPCORN network sites, which span eight provinces, the CURNLS study will provide relatively broad and representative seroprevalence data among children and youth across Canada,” says Dr. Quach-Thanh. By testing for antibodies to SARS-CoV-2, including nucleocapsid (N), spike (S) and receptor-binding domain (RBD) antigens, the CURNLS researchers have several goals. “We aim to determine the rates of seropositivity due to infection and vaccination, the differences in seroprevalence among children of different ages and from different regions of Canada, and the associations between serologic measures and trends of viral transmission and vaccination rates,” says Dr. Quach-Thanh.

Five times during the coming year, approximately 7,200 samples will be obtained and tested through the new study. Analyses will be performed according to three distinct age groups within the 0 to 18 range.

“The CITF funds several studies, including among blood donors via Canadian Blood Services and Héma-Québec, that provide valuable seroprevalence data for adults on an ongoing basis, but until now there has been no nationally representative and ongoing pediatric population included,” says Dr. Tim Evans, CITF executive director. “The CURNLS study is the first national serosurvey focussing on children and teens, and the data it generates on SARS-CoV-2 infection and immunity will help predict future pandemic trends, understand the spectrum of disease arising from infection in this age group, the role of children in community transmission, and the need for additional vaccination and/or public health measures.”

About the COVID-19 Immunity Task Force
The Government of Canada established the COVID-19 Immunity Task Force (CITF) in late April 2020 to catalyze, support, fund, and harmonize research on SARS-CoV-2 immunity for federal, provincial, and territorial decision makers in their efforts to protect Canadians and minimize the impact of COVID-19. The Task Force and its Secretariat work closely with a range of partners, including governments, public health agencies, institutions, health organizations, research teams, other task forces, engaging communities and stakeholders. To date, the CITF has supported over 110 studies across Canada that are generating critical insights on the levels, trends, nature, and duration of immunity arising from SARS-CoV-2 infection and COVID-19 vaccination. The CITF is overseen by an Executive Committee of volunteers that includes leading scientists and policymakers from across Canada.

About Canadian Institutes of Health Research
At the Canadian Institutes of Health Research (CIHR), we know that research has the power to change lives. As Canada’s health research investment agency, we collaborate with partners and researchers to support the discoveries and innovations that improve our health and strengthen our healthcare system.