Pfizer says its COVID-19 vaccine protects younger teens

Pfizer announced Wednesday that its COVID-19 vaccine is safe and strongly protective in kids as young as 12, a step toward possibly beginning shots in this age group before they head back to school in the fall.

Most COVID-19 vaccines being rolled out worldwide are for adults, who are at higher risk from the coronavirus. Pfizer’s vaccine is authorized for ages 16 and older. But vaccinating children of all ages will be critical to stopping the pandemic — and helping schools, at least the upper grades, start to look a little more normal after months of disruption.

In the vaccine study of 2,260 U.S. volunteers ages 12 to 15, preliminary data showed there were no cases of COVID-19 among fully vaccinated adolescents compared to 18 among those given dummy shots, Pfizer reported.

It's a small study, that hasn't yet been published, so another important piece of evidence is how well the shots revved up the kids’ immune systems. Researchers reported high levels of virus-fighting antibodies, somewhat higher than were seen in studies of young adults.

Kids had side effects similar to young adults, the company said. The main side effects are pain, fever, chills and fatigue, particularly after the second dose. The study will continue to track participants for two years for more information about long-term protection and safety.

Dr. Philip J. Landrigan of Boston College said the results are encouraging.

“It’s hard to get kids to comply with masking and distancing, so something that gives them hard protection and takes them out of the mix of spreading the virus is all for the good,” said Landrigan, who was not involved in the study.

It’s another positive development in the race against the virus even as U.S. cases, at 66,000 new infections a day, are rising again and deaths are averaging nearly 1,000 a day. Centers for Disease Control and Prevention director Dr. Rochelle Walensky warned Americans again Wednesday that “we can’t afford to let our guard down.”