COVID vaccine 73.2 percent effective in children under 5: Pfizer

Participants in the study received either the Pfizer-BioNTech COVID-19 Vaccine (3-μg) as a three-dose series or placebo (2:1 randomization). Vaccine efficacy, a secondary endpoint in the trial, was 73.2% (2-sided 95% CI: 43.8%, 87.6%) among children 6 months through 4 years of age without evidence of prior COVID-19 infection. This analysis was based on 13 cases in the Pfizer-BioNTech COVID-19 Vaccine group (n=794) and 21 cases in the placebo group (n=351), diagnosed from March to June 2022. The study protocol specified that this formal efficacy analysis should be performed when at least 21 total symptomatic COVID-19 cases were identified, each at least seven days after the third dose. Consistent with the time period when the cases occurred, sequencing of viral RNA from illness visit nasal swabs indicated that observed cases were primarily caused by Omicron BA.2. Omicron BA.4 and BA.5 strains were emerging during the period of the study, with only a few cases accrued and efficacy results against these strains were inconclusive. "Consistent with our approach in adults, we are working with the FDA to prepare an EUA application for an Omicron BA.4/BA.5-adapted bivalent vaccine in children 6 months through 11 years of age," the release stated.

"Building on the strong safety and immunogenicity data that led to FDA authorization of our COVID-19 vaccine for children 6 months through 4 years, we are pleased to share confirmatory evidence that a full course of vaccination helps protect against symptomatic disease, particularly during a time when the Omicron BA.2 strain was predominant," said Albert Bourla, Chairman and Chief Executive Officer, Pfizer.

"While these results confirm that three 3-µg doses of our COVID-19 vaccine provide young children with a high level of protection at a time when the Omicron BA.2 strain was highly prevalent with a favorable safety profile, we are also developing an Omicron BA.4/BA.5-adapted bivalent vaccine in this age group to address these sublineages," said Prof. Ugur Sahin, M.D., CEO and Co-Founder of BioNTech.

Among children ages 6 through 23 months, the vaccine was 75.8% (2-sided 95% CI: 9.7%, 94.7%) effective at preventing COVID-19, based on 4 cases in the vaccine group (n=296) and 8 cases in the placebo group (n=147), after a median of 1.9 months (range: 0.0, 4.9) follow-up after the third dose. For children ages 2 through 4 years of age, the vaccine was 71.8% (2-sided 95% CI: 28.6%, 89.4%) effective at preventing COVID-19, based on 9 cases in the vaccine group (n=498) and 13 cases in the placebo group (n=204), after a median of 2.4 months (range: 0.0, 4.9) follow-up after the third dose.

Three 3-µg doses of the Pfizer-BioNTech COVID-19 Vaccine continue to be well-tolerated in this age group. 

On July 8, Pfizer and BioNTech submitted safety and immunogenicity data to the European Medicines Agency (EMA) requesting an update to the Conditional Marketing Authorization (CMA) in the European Union (EU) to include children ages 6 months through 4 years. The companies plan to submit the updated efficacy data to the FDA, EMA and other regulatory agencies around the world in the coming weeks.

The Pfizer-BioNTech COVID-19 Vaccine, which is based on BioNTech's proprietary mRNA technology, was developed by both BioNTech and Pfizer. BioNTech is the Marketing Authorization Holder for BNT162b2 (COMIRNATY) in the United States, the European Union, the United Kingdom, Canada and other countries, and the holder of emergency use authorizations or equivalents in the United States (jointly with Pfizer) and other countries. Submissions to pursue regulatory approvals in those countries where emergency use authorizations or equivalent were initially granted are planned.