Unvaccinated students eight times more likely to get COVID-19 than vaccinated peers

The incidence of COVID-19 was eight times higher in unvaccinated students compared with their vaccinated peers, according to a research brief published in Pediatrics.

Researchers from Duke University said that “clinical trials have shown SARS-CoV-2 vaccines to be safe and efficacious for adults, adolescents and young children,” but “in some areas, vaccine uptake has been low among children and adolescents, especially compared to uptake in adults. Additionally, real-world vaccine effectiveness data among adolescents and implications for in-person education are lacking.”

Ibukun C. Kalu, MD, an assistant professor of pediatrics at the Duke University School of Medicine, and colleagues investigated the impact of COVID-19 vaccination in a cohort of 1,128 students aged 11 to 19 years, all of them attending grades 6 to 12 at a North Carolina private school from Aug. 1, 2021, to Nov. 12, 2021. During this period, the school mandated universal indoor masking and a hybrid in-person and remote learning schedule, with only two documented cases of in-school transmission. During this period, the county where the school was located was categorized by the CDC as a high-transmission area, with the delta variant comprising more than 99% of the area’s cases.

According to the researchers, 829 (73.5%) students were vaccinated, whereas the remaining 299 (26.5%) students were unvaccinated. A total of 20 (6.7%) unvaccinated students reported being infected during the study period vs. only seven (0.8%) vaccinated students.

The unvaccinated students had 8.2 (95% CI 3.5-19.4) times the incidence of documented infection and 9.2 (95% CI 3.4-25.1) times the incidence of symptomatic infection compared with vaccinated students, according to the researchers.

Kalu acknowledged that the study was limited to only one school, but the findings add to mounting evidence nationwide showing “the usefulness of vaccinations.”

“I would encourage people to continue to [track] the impact of COVID-19 but also vaccinations and treatment options for children,” she said.