- Pfizer and BioNTech will ask regulators to approve a booster dose of their Covid-19 vaccine for children between the ages of 5 and 11 after a third shot sparked a strong immune response in clinical testing.
- A late-stage trial of 140 volunteers showed that children had higher levels of virus-fighting antibodies a month after a booster than they did a month after completing the original two-shot series, the companies said Thursday. An analysis of 30 blood samples also suggested the booster strengthened their defense against the omicron variant.
- The two companies plan to seek Food and Drug Administration clearance of a booster in the coming days and said they will move quickly to consult with other regulators around the world.
The request to market a booster dose is the natural next step for Pfizer and BioNTech, who won FDA clearance for their vaccine in children between the ages of 5 and 11 in late October. Many kids in the age bracket received their first two doses in November, meaning they would be eligible for a booster in late May under the six-month timeframe studied by researchers.
U.S. authorities have already cleared booster shots for everyone 12 years and older, and a number of adults are also eligible for a second booster, having received their original inoculations in early 2021. The Centers for Disease Control and Prevention plans to convene its advisory panel on April 20 to further discuss boosters and make recommendations.
The picture is still murky for children younger than 5, however. Two doses of Pfizer and BioNTech’s shot weren't potent enough in clinical testing, leading the companies to begin studying the effects of a third dose. In February, they abandoned a plan to seek authorization of the first two doses while continuing to gather data on the third. (Moderna intends to evaluate a third shot of its vaccine as well, but nonetheless decided in March to seek clearance of a two-dose regimen in children as young as 6 months old age.)
More broadly, vaccine makers and regulators are struggling with how to adapt vaccines to fight new variants. FDA advisory committee members agreed earlier this month that the vaccines will probably need updates but said they need more information to give specific guidance.