School closures didn’t prevent community spread of COVID-19: study

McMaster University researchers have found that when masking and vaccinations were used, schools were not a major source of COVID-19 transmission.

“After that initial shutdown and stay at home order had (been) put in place, in later periods, when schools were reopened or closed, we didn’t see an impact on community-level transmission,” said Sarah Neil-Sztramko, a professor in health research at McMaster and lead author of the study. “Rather, the patterns of transmission we saw in schools was much more reflective of what was already happening in the community.”

The research shows that children in daycares and students in elementary and high school can stay in the classroom when certain infection prevention and control measures are in place because removing them did not result in spikes of COVID-19 in the broader community.

“Vaccination, not surprisingly, was really effective in those school settings to prevent transmission. Masking was also one of the more effective interventions,” Neil-Sztramko said.

Test-to-stay policies were also effective at mitigating COVID-19’s spread in schools and daycares. This allowed children who tested negative after a confirmed case in a class to attend school instead of having everyone be part of a two-week quarantine at home.

Measures such as cohorting and distancing policies, however, “didn’t seem to make as much of a difference,” Neil-Sztramko added, because of children’s inability to adhere to them in school settings.

Schools closure in response to COVID-19 lasted longer in Ontario than in any other province.

Lisa Wagowsky, a mother of three in Toronto, said she often wondered if keeping schools closed was doing “more harm than good.”

“The masks, the screening ,the COVID tests that were readily available, the cohorting, we had the sense that these were effective,” she said, adding “the one thing my seven-year-old daughter at the time learned was how to click on YouTube videos.”

The researchers started reviewing evidence in May 2020 and updated their work 18 times over the course of the pandemic. The final version of their study was published in the medical journal the Lancet Child and Adolescent Health.

“Things changed along the way,” Neil-Sztramko said. “Variants of concern became more prevalent when vaccinations became more broadly available. The data that we had and the context that we were working with, with transmission in schools and daycares and in other settings, changed.  That’s why we continued to update, this review… so that we could provide decision-makers with the most up to date information.”

Researchers hope the findings will provide a strong and factual foundation on how to properly deal with significant outbreaks caused by future variants or other infectious diseases.