Pfizer says its COVID-19 shot is safe for kids under 5

Study finds it over 80% effective against omicron

Pfizer-BioNTech’s COVID-19 vaccine appears to be safe and effective for children ages 6 months to under 5 years, according to a company study released early Monday.

The study of nearly 1,700 children showed the vaccine was as safe as a placebo and more than 80% protective during the omicron outbreak. No new safety concerns were identified during the trial, the companies said in a news release, and the majority of reported adverse events were mild or moderate.

Pfizer and its partner BioNTech have been testing their COVID-19 vaccine in children under 5 since last year. Company research suggested two shots would not be enough to prevent illness in that age group during the omicron outbreak, so the companies added a third shot to the regimen.

Effectiveness is still unconfirmed in this age group, awaiting more infections, but only 10 children in the trial developed symptomatic cases as of April 29, the companies said. The trial protocol specified a formal effectiveness analysis would be done once at least 21 children developed symptomatic cases.

The vaccine is the same as is given to older children and adults, but the dose for younger children is 3 micrograms, one-tenth the size of the adult dose.

Moderna also has developed a vaccine for younger children that is being reviewed by the FDA. That vaccine also appears to be safe but less effective than shots for adults.

In Moderna’s study of 6,700 children ages 6 months to under 6, researchers found that children who received two shots of a 25-microgram dose developed similar levels of virus-fighting antibodies as young adults who received two doses of the full-strength 100microgram vaccine. In the study, which took place during the omicron wave, researchers found the vaccine was 51% effective among children 6 months to under 2 and 37% effective among children 2 to under 6.

The FDA has promised to rapidly review the safety and effectiveness data in younger children and plans an advisory panel meeting as soon as June 8 to discuss authorizing shots in that age group.

Pfizer and BioNTech have not yet provided their complete data to the FDA but expect to within about a week, according to the companies.

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