Largest study on COVID-19 in Canadian children and teens now underway

By UdeMnouvelles Oct 6th, 2022

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In 5 seconds Led by Université de Montréal and CHU Sainte-Justine, the $2.6-million CURNLS study will collect and test about 7,200 blood samples over the coming year to check for past infection and immunity.

In Canada, the vast majority of COVID-19 cases in the 0-to-18 age group have been mild or asymptomatic. Combined with the reduction in routine COVID-19 laboratory testing across most of the country, this means that the infection rates in children and adolescents are largely unknown. And 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 Canadian government and the Canadian Institutes of Health Research, 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.

Benefiting from the network established for an existing CIHR-funded project called Pediatric Outcomes Improvement through Coordination of Research Networks (POPCORN), the study is called CURNLS, short for ‘COVID-19 seroepidemiology among children Using Retrieved POPCORN Site Leftover blood Samples.’

It is led by Drs. Soren Gantt and Caroline Quach-Thanh, investigators at CHU Sainte-Justine Research Centre and professors at Université de Montréal. POPCORN is also led by Dr. Quach-Thanh and brings together pediatric health researchers from 16 Canadian hospital research sites 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,” Gantt explained. “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,” said Quach-Thanh.

By testing for antibodies to SARS-CoV-2, including nucleocapsid, spike and receptor-binding domain (RBD) antigens, the CURNLS researchers have several goals, she added.

“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.”

Some 7,200 blood samples

Five times over 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,” said CITF executive director Dr. Tim Evans.

“The CURNLS study is the first national serosurvey focusing on children and teens,” he said, “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.”

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