COVID-19 vaccine is strongly effective for children and adolescents during delta and omicron

A health record analysis shows that the risk of infection and severe illness is significantly lower for those who are vaccinated, and cardiac conditions do not increase.

A medical professional puts a bandage on a teen’s arm after vaccination.
Image: iStock/MilanMarkovic

Children and adolescents who received one of the main COVID-19 vaccines are significantly protected from the illness and showed no increased signs of cardiac complications compared to young people who were not vaccinated, according to a new real-world study led by researchers from the Perelman School of Medicine and Children’s Hospital of Philadelphia (CHOP). When the delta variant rose to prominence, the study shows that vaccinated young people are 98% less likely to be infected than their unvaccinated peers, and data indicates that the vaccine’s effectiveness declined slightly when the omicron variant became dominant. The paper is published in Annals of Internal Medicine.

In their analysis of 250,000 patients, where around half of them received at least one dose of the BNT162b2 vaccine (the vaccine produced by a collaboration between Pfizer and BioNTech), the researchers—led by Yong Chen and Jeffrey Morris, both professors of biostatistics at the Perelman School of Medicine, and Christopher Forrest, a professor of pediatrics at CHOP and Penn—covered the periods in which the delta and omicron variants became dominant, in mid-2021 and 2022, respectively.

While previous clinical trials established that the vaccines provided strong protection against infection for children and adolescents, limited evidence of the vaccine’s performance existed beyond controlled settings. So, the researchers conducted one of the largest “real-world” COVID-19 vaccine studies of children and adolescents in the United States, with the assistance of data from electronic health records gleaned from a national network of pediatric medical centers, known as PEDSnet. In so doing, the study provides a picture of the vaccine’s effectiveness outside of controlled trial conditions, in the “real world” of visits to pediatricians, family medicine doctors, emergency departments, and more.

“Our study has longer follow-up than any previous study, which enabled us to evaluate the real-world, long-term durability of vaccine protection against delta and omicron variants,” says Chen. “Further, it covered a diverse representation of U.S. pediatric populations from primary care, specialty care, emergency department, testing centers, and inpatient settings.”

Read more at Penn Medicine News.