Pfizer shot found fully effective in teens

US drugmaker Pfizer on Wednesday reported that a COVID-19 vaccine that it co-developed was 100 percent effective against the disease in clinical trials of adolescents.

The findings may lead to vaccinations in the United States for middle school students before school starts this fall. The trial subjects were aged from 12 to 15.

In the Pfizer trial, 2,260 minors in the US were enrolled. The vaccine was 100 percent effective in protecting against symptomatic disease and elicited robust antibody responses one month after the second dose, exceeding those reported in trials of adults in an earlier analysis. Pfizer developed the vaccine with German partner BioNTech.

Pfizer CEO Albert Bourla said the company plans to submit the data to the FDA in the coming weeks to amend the current emergency use authorization, expanding the use of the shots to 12-to 15-year-olds, and "with the hope of starting to vaccinate this age group before the start of the next school year".

In an updated data on Thursday, Pfizer said the vaccine is around 91 percent effective at preventing the disease, in a separate trial that included participants inoculated for up to six months.

For the trial involving 12-15 year olds, researchers will continue to monitor them for long-term protection and safety for an additional two years after their second dose, according to Pfizer.

Scott Gottlieb, a former commissioner at the FDA and a member of the board of Pfizer, told CNBC on Wednesday that he expects it will take the agency about a month to review the new data. If the FDA process goes well, the vaccine could be available by the fall.

The Pfizer-BioNTech vaccine is currently authorized in the US for emergency use in people 16 and older.

Moderna is also testing its vaccine in adolescents and children, in two clinical trials of children aged 12 to 17 and those ages 6 months to 11 years.