COVID-19: Pfizer injections seem effective for children under 5

Pfizer’s COVID-19 vaccine was 73% effective in protecting children under 5 as Omicron spread in the spring, the company announced Tuesday.

Vaccinations for babies, toddlers and preschoolers opened in the United States in June after months of delay. According to the American Academy of Pediatrics, only about 6% of young people aged 6 months to 4 years had received at least one dose of a COVID-19 vaccine by mid-August.

Health authorities have authorized tot-sized vaccine doses made by Pfizer and its partner BioNTech based on a study showing they were safe and produced high levels of anti-virus antibodies. But there was only preliminary data on how this translated to efficacy against symptomatic COVID-19.

The new update analyzed COVID-19 diagnoses between March and June as part of Pfizer’s ongoing three-dose vaccine study. There have been 21 cases of COVID-19 among the 351 toddlers who received dummy vaccines – compared to just 13 among the 794 youngsters who received three doses of the vaccine.

The child cases were mainly caused by the BA.2 Omicron version that was circulating at the time. Today, another Omicron relative, BA.5, is the source of most COVID-19 cases in the United States and much of the world.

In older children and adults, COVID-19 vaccines have been used long enough to prove that they remain strongly protective against severe illness and death, even when the coronavirus mutates – while early protection against infection decreases. Still, scientists are tracking that initial rate of effectiveness as further proof of the vaccine’s performance — and to look for signs of how well they initially resist new mutants.

Pfizer asked U.S. regulators this week to allow modified vaccine doses that better match new Omicron variants for people 12 and older as boosters this fall. The company said it was also developing updated plans for children under 12.


The Associated Press Health and Science Department is supported by the Howard Hughes Medical Institute Department of Science Education. The AP is solely responsible for all content