In a late-stage trial studying more than 2,200 adolescents in the US, not a single vaccinated person became infected with COVID-19, Pfizer said in a press release. The results suggest the Pfizer-BioNTech vaccine may be even more effective in 12- to 15-year-olds than it is in adults.
Pfizer has not yet released the trial data. The company plans to submit the results to the FDA in the coming weeks, said chief executive Albert Bourla, "with the hope of starting to vaccinate this age group before the start of the next school year.”
If it wins emergency authorization, Pfizer's vaccine will be the first in the United States to be given out to children younger than 16. Public health experts believe that vaccinating children will be crucial toward achieving "herd immunity" — when so many people have immunity to COVID-19 that the virus is no longer able to spread effectively. President Joe Biden has called for immunizing high school–age students by the fall in the US and elementary school ones early in 2022, if trial results like the one announced by Pfizer show the vaccines are indeed safe and effective among them.
Pfizer said the trial showed the vaccine to be safe in 12- to 15-year-olds, with side effects "generally consistent with those observed in participants 16 to 25 years of age."
Pfizer's vaccine was first authorized for emergency use for people 16 and older in December, and more than 75 million doses have been given to Americans since then. A clinical trial last fall found it was 95% effective in reducing COVID-19 infections in adults; a recent study showed similar 90% effectiveness results in the "real world" since its authorization.
In the announcement, Pfizer also said it has started vaccinating children aged 5 to 11 in a related global trial and will start next week giving it to a group of children aged 2 to 5.