Pfizer, BioNTech report 80 percent efficacy of Covid-19 vaccine for youngest children

No children in the trial had any serious side effects, the release said.

“These topline safety, immunogenicity and efficacy data are encouraging, and we look forward to soon completing our submissions to regulators globally with the hope of making this vaccine available to younger children as quickly as possible, subject to regulatory authorization,” Albert Bourla, Pfizer’s chief executive officer, said in a statement.

Background: Pfizer and BioNTech initially asked the FDA to authorize their two-shot Covid-19 regimen for kids 6 months to under 5 in February. The agency delayed the advisory committee meeting that would discuss the vaccine for this population, opting to wait for more data on a third dose. Pfizer tested a dose for children equal to about one-tenth of what adults received. Two kid-sized doses in children 6 to 24 months old generated immunity comparable to that in young adults who received two full doses. The same two pediatric doses didn’t generate similar immunity in children 2 to 5 years old.

The companies collected data on three doses of their vaccine in 1,678 children who received their third shot at least two months after they received their second, the release said. Omicron was the dominant variant of Covid-19 circulating at that time.

In late April, Moderna asked the FDA to authorize its two-dose Covid-19 vaccine for the same age group. Late-stage clinical trials showed that pediatric doses of its vaccines generated comparable immunity in the youngest children as two full doses did in young adults.

However, Moderna’s vaccine reduced symptomatic Covid-19 cases by 43.7 percent among children 6 to 24 months old and by 51 percent of cases detected by PCR tests. For kids 2 to 6 years old, it reduced symptomatic cases by 35.7 percent and PCR-detected cases by 37 percent.

What’s next: Pfizer expects to complete its submission to the FDA this week, according to the release. The FDA will schedule an advisory committee meeting to discuss the companies’ application when they complete their data submission.