Canada’s immunity task force is turning its attention to the country’s youngest people in an effort to better understand the extent to which they contribute to the spread of COVID-19 and how the disease varies across the age spectrum.
On Tuesday, the COVID-19 Immunity Task Force announced it was supporting a new study led by the BC Children’s Hospital that will test thousands of individuals – from newborns to 24-year-olds – to determine how many have already contracted the coronavirus, even if they were unaware of it. Three studies of children that are already up and running across the country will also receive support from the task force.
The studies resemble others across Canada that screen large numbers of individuals for antibodies to the coronavirus. The difference is that most of those studies have not included children. The new research will offer another clue to how COVID-19 is moving through the population and could inform strategies for vaccine deployment next year.
“We really have to understand children in terms of their susceptibility to infection, but also their role in transmission of infection in households,” said Tim Evans, who leads McGill University’s School of Population and Global Health and is the executive director of the task force.
The B.C. project, dubbed the SPRING study, will build a sweeping portrait of the pandemic among young people in the province and track its movement through time. Parents who wish to enroll their children in the study will be asked to fill out an online questionnaire and provide blood spots on paper using a finger prick test kit. Such tests do not reveal active cases of COVID-19 but instead are used to determine if someone contracted the virus at some point.
The study seeks to address some of the lingering mysteries around the coronavirus in children, including whether they are less likely to become infected or whether their infection rates are similar to those of adults but with fewer symptoms. Other studies have provided conflicting answers, which has made it hard to predict transmission rates in schools and other settings where children are interacting with each other and with adults.
Study leader Manish Sadarangani, the director of the hospital’s vaccine evaluation centre, said comparatively low case numbers of COVID-19 among children do not mean children will not be an important consideration during a vaccine rollout.
“When the first wave of vaccines are available … clearly kids are not going to be a high priority for vaccination,” he said. “But I think moving further down the line, we know, from influenza, that vaccinating children is really important because it breaks transmission to the elderly.”
Dr. Sadarangani added that he and his colleagues initially intended to look only at children from newborns to age 18. But they expanded the study to include young adults in order to capture how much COVID-19 has penetrated an age group that was one of the first to see a rise in case counts this summer.
“We’re planning to recruit equally at different ages,” from preschool to university age, he said. The study will also sample from across the province and will include a diverse and representative range of participants.
If it manages to recruit widely enough, the results could improve computer models that try to predict the trajectory of the pandemic, particularly in settings where children comprise a significant share of the population. The key is to have a better handle on transmission rates among children.
“If we can compare that to adults then we’ll have some information about how COVID is spreading in schools,” said Caroline Colijn, a mathematician and disease modeller at Simon Fraser University in Burnaby, B.C., who is not involved with the Children’s Hospital study.
The SPRING study ultimately aims to include 16,000 participants, but Dr. Sadarangani said the immediate goal is to recruit 2,500, divided evenly among five groups according to age, then follow those groups as the pandemic ebbs and flows. So far 300 have signed on since recruiting began two weeks ago.
The study has received $1.3-million from the COVID-19 Immunity Task Force. Funding has also been allocated to studies tracking COVID-19 in children and teens in Montreal (EnCORE study) and two cohort studies led by researchers at McMaster University in Hamilton (CHILD study) and Toronto’s Hospital for Sick Children (TARGet Kids.)
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