Pfizer-BioNTech COVID shot 73.2% effective in kids under 5

Pfizer Inc's COVID-19 vaccine was 73.2% effective in children aged between 6 months and 4 years, the company's data showed on Tuesday, two months after the U.S. rollout of the shots began for that age group.

Pfizer and BioNTech's vaccine was authorized for children under 5 years of age in June, based on data that showed the vaccine generated a similar immune response to those seen in older age groups.

An early analysis based on 10 symptomatic COVID-19 cases in the study had suggested a vaccine efficacy of 80.3% in this group, but experts had warned that the data was preliminary due to the low number of symptomatic cases.


The updated data released on Tuesday showed 13 children had COVID-19, at least seven days after receiving a third dose of the Pfizer-BioNTech COVID-19 vaccine, compared with 21 cases in those who received a placebo.

Most cases were caused by the Omicron BA.2 variant that was dominant in March and April, when the study was conducted.

The companies also said they were preparing an application seeking U.S. authorization for an Omicron-targeting vaccine booster in children aged 6 months through 11 years of age.