Pfizer’s vaccine prevents severe illness in children ages 5 to 11 but data from a New York study shows it may offer little protection against infection.
The study, published Monday, found the effectiveness of the Pfizer/BioNTech vaccine against COVID-19 infection plummeted from 68% to 12% for children aged 5 to 11 during the omicron surge, which was first identified in the fall.
Protection against hospitalization dropped by more than half from 100% to 48% from December through the end of January.
The study has not been peer-reviewed.
The study was conducted by a team of public health officials in New York who said the drop in vaccine effectiveness was likely due to the lower dosage of the vaccine that children receive.
Children ages 5 to 11 receive two 10-microgram shots, while those over age 12 receive two 30-microgram shots.
Vaccine effectiveness also dropped for children ages 12 to 17 years old, though the drop was not as dramatic. For those 12 to 17, vaccine effectiveness against infection dropped from 66% to 51% from mid-December through the end of January.
Protection against hospitalization dropped from 85% to 73% for teenagers during the same period.
“Given rapid loss of protection against infections, these results highlight the continued importance of layered protections, including mask wearing, for children to prevent infection and transmission,” the public health officials wrote in the study.
Dr. Kathryn M. Edwards, a pediatric vaccine expert at Vanderbilt University, echoed the idea that the protection that the vaccine gives against severe disease is needed.
“We need to make sure we emphasize the doughnut and not the hole,” said Edwards told The New York Times.
As of this weekend, the U.S. reported a daily average of nearly 66,000 new infections, according to Johns Hopkins University.