In the updated analysis, the Pfizer-BioNTech Covid-19 vaccine showed 73.2% efficacy in children aged six months to four years, 75.8% efficacy in children aged six to 23 months, and 71.8% efficacy in children aged two to four years
Pfizer and BioNTech unveiled updated efficacy data. (Credit: Mat Napo on Unsplash)
Pfizer and BioNTech announced that their three-dose Covid-19 vaccine regimen showed 73.2% vaccine efficacy in children aged six months to four years, based on updated efficacy data from a Phase 2/3 trial.
The previous efficacy analysis, announced earlier this year, showed an 80.3% vaccine efficacy, based on 10 symptomatic Covid-19 cases in the study.
However, the experts cautioned that the data was preliminary due to a low number of symptomatic cases, according to Reuters report.
In the updated analysis, the vaccine showed 73.2% efficacy in children aged six months to four years, based on 13 cases in the vaccine arm and 21 in the placebo arm.
The Pfizer-BioNTech Covid-19 vaccine demonstrated 75.8% efficacy in children aged six to 23 months, and 71.8% efficacy in children aged two to four years.
The updated results complemented the previously announced efficacy analysis, said Pfizer.
Pfizer chairman and chief executive officer Albert Bourla said: “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.
BioNTech co-founder and CEO Ugur Sahin said: “we are also developing an Omicron BA.4/BA.5-adapted bivalent vaccine in this age group to address these sub-lineages.
The Phase 1/2/3 trial enrolled more than 10,000 children, aged six months to 12 years, in more than 90 clinical trial sites across the US, Finland, Poland, Brazil, and Spain.
The study evaluated the safety, tolerability, and immunogenicity of the three-dose vaccine regimen in children aged five to 11 years, two to five years, and six months to two years.
In the trial, children aged five to 12 years received a two 10µg doses, while those aged below five years received a 3µg dose each, with vaccine efficacy as a secondary endpoint.
In addition, the three-dose Covid-19 vaccine regimen was well-tolerated in this age group, with a safety profile similar to placebo, said Pfizer.
In June this year, the US Food and Drug Administration (FDA) granted Emergency Use Authorization (EUA) for the Pfizer-BioNTech Covid-19 vaccine in this age group.
In addition, the European Medicines Agency (EMA) is currently reviewing an application for conditional Marketing Authorisation (CMA) of the vaccine in this age group.
Last month, Pfizer and BioNTech submitted safety and immunogenicity data to the EMA seeking an expanded CMA to include children ages six months through four years.
Furthermore, the companies intend to submit the updated efficacy data to the FDA, EMA, and other regulatory agencies worldwide, in a few weeks.