Pfizer shot found 100% effective on adolescents in trials

The Pfizer-BioNTech COVID-19 vaccine was 100 percent effective in clinical trials of adolescents aged 12-15 years, the company said Wednesday. The findings may lead to vaccinations for middle school students before school starts this fall.

Meanwhile, about 15 million doses of Johnson & Johnson's one-dose vaccine were ruined when workers at a Baltimore plant manufacturing two coronavirus vaccines accidentally put together the vaccines' ingredients several weeks ago, The New York Times reported Wednesday.

The mix-up has halted future shipments of J&J's vaccine in the United States while the Food and Drug Administration investigates. J&J's doses currently being delivered and used nationwide aren't affected. All those doses were produced in the Netherlands, where operations have been fully approved by federal regulators.

The plant is run by Emergent BioSolutions, a manufacturing partner to both J&J and AstraZeneca. Federal officials attributed the mistake to human error.

In a trial that enrolled 2,260 participants in the US, the Pfizer 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 CEO Albert Bourla said the company plans to submit the data to the US Food and Drug Administration (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 the trial, researchers observed 18 cases of COVID-19 among the 1,129 participants who were given a placebo versus none among the 1,131 participants who got the vaccine. The data has yet to be peer-reviewed.

Children in the studies reported adverse reactions like fatigue and headaches that were consistent with those reported by young adults in the vaccine's larger pivotal trial, Pfizer said.

To further study the safety of the vaccine, researchers will continue to be monitored for long-term protection and safety for an additional two years after their second dose, according to Pfizer.

Dr 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.

Pfizer and BioNTech started testing the vaccine in children ages 6 months to 11 years last week when the first children ages 5 to 11 received a shot. The company plans to begin dosing 2- to 5-year-olds next week and work its way down to participants ages 6 months to 2 years. The company aims to enroll 4,644 children in the trial and expects results by the end of 2021.

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

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

Vaccinating children is crucial to reaching herd immunity and ending the pandemic, public health officials and infectious disease experts say. Herd immunity is when enough people in a given community have antibodies against a specific disease.

Children make up around 20 percent of the US population, according to government data. Between 70 percent and 85 percent of the US population needs to be vaccinated against COVID-19 to achieve herd immunity, experts say.

"We all long for a normal life. This is especially true for our children," said BioNTech CEO Ugur Sahin in the press release.