FDA asks Pfizer, Moderna to test vaccines in more children to help rule out safety issues

Federal regulators have requested that vaccine companies expand their trials to test coronavirus shots in several thousand school-aged children before seeking authorization — a move intended to assess whether a rare inflammation of the heart muscle that has been seen in young adults shortly after vaccination is more common in younger age groups.

The changes to ongoing trials run by Moderna and Pfizer and its German partner BioNTech could delay the availability of the vaccines to children between the ages of 5 and 11 beyond the hoped-for timeline of early fall, although it is unclear by how much. As the country faces a surge fueled largely by cases in unvaccinated people and the school year approaches, pediatricians and families have impatiently awaited shots of protection.

At a CNN town hall meeting last week, President Joe Biden erroneously said that children under 12 might have access to a vaccine as soon as August, a timeline that has never been projected by any company working on a pediatric vaccine.

A federal official who spoke on the condition of anonymity predicted that authorization of a coronavirus vaccine for children 5 through 11 might come by late October or early November. The government is not expecting it will be a big problem to enroll more children because so many parents are eager to get their children vaccinated, the official said.

Ray Jordan, a spokesman for Moderna, said the company was “actively discussing a proposal” with federal regulators to expand its trial, but had not settled on final numbers for the expanded trial. He predicted that authorization could occur in “winter 2021/early 2022.”

“The objective is to enroll a larger safety database which increases the likelihood of detecting rarer events,” Jordan said in an email. The original trial included nearly 7,000 children from 6 months to 12 years old.

Jerica Pitts, a spokeswoman for Pfizer, said that the company hasn’t yet made any updates to its trial design or its timeline, which was originally predicted to report results in September for children aged 5 to 11 years old, with results for children age 2 to 5 expected to follow shortly and for children as young as 6 months in October or November.