Vaccine for children under five delayed by at least 2 months in US

WASHINGTON • A US decision on Pfizer and BioNTech's Covid-19 vaccine for infants and children six months through four years of age has been postponed for at least two months after the Food and Drug Administration (FDA) said it needed more data.

The FDA had planned to decide on the vaccine based on early trial data as soon as next week with the government planning to roll it out on Feb 21. It had asked Pfizer to speed up its application as the Omicron variant of the coronavirus caused a surge of infections, including among children.

On Friday, it said it had reviewed new trial information that arrived after Pfizer and BioNTech's request for emergency authorisation and decided it needed more data before weighing in on the authorisation.

It said parents anxiously awaiting the vaccine for the roughly 18 million children in the age group should be reassured it is taking the time to make sure it meets the standard it has set for authorisation."If something does not meet that standard, we can't proceed forward," said Dr Peter Marks, director of the FDA's Centre for Biologics Evaluation and Research. He noted some of the new data that pushed the FDA to delay the decision was "late-breaking".

Pfizer and BioNTech had submitted data on the first two doses of a planned three-dose regimen earlier this month at the request of the FDA. It did not disclose efficacy data. The submission was surprising because in December, the firms said early trial results of the two low doses of the vaccine fell short of expectations, and amended its clinical trial to test a three-dose version.

The companies said on Friday that they expect to have data on three shots in early April.

"It makes sense to wait for the safety and efficacy data on all three doses to be available before we make a decision about this vaccine," said Dr Paul Offit from Children's Hospital of Philadelphia. He is a member of the FDA's Vaccines and Related Biological Products Advisory Committee scheduled to vote on whether to recommend authorisation of the shot for kids under 5 on Tuesday. The meeting was postponed.

The primary series of the Pfizer-BioNTech vaccine has been two doses in all older age groups. But Pfizer began testing a third dose in the younger age group because early results showed the lower dose generated an immune response in two-to four-year-olds that was inferior to the response measured in those aged 16 to 25 in previous clinical trials. In six-month-old to 24-month-old children, the vaccine generated an immune response in line with 16-to 25-year-olds.

Dr Amesh Adalja, an infectious disease expert at the Johns Hopkins Centre for Health Security, said there had been considerable push-back among scientists about the FDA's decision to pursue authorisation so quickly.

"This age group is very low-risk for severe disease and vaccine uptake in the five to 11 (age group) has been very suboptimal. It's critical that people have confidence in the process if higher vaccine uptake is the goal," he said.

REUTERS