Trial shows Pfizer-BioNTech jab safely bolsters antibodies in kids aged 5 to 11

NEW YORK • Pfizer and its partner BioNTech said their Covid-19 vaccine was safe and produced strong antibody responses in children aged five to 11 in a large-scale trial, findings that could pave the way to begin vaccinating grade-school kids within months.

The long-awaited results offer an early look at how well a coronavirus vaccine could work for younger children. Pressure to immunise kids has been on the climb in the United States, where a new school year has started just as the Delta variant is fuelling a surge in cases.

In a trial with 2,268 participants, two shots of a 10mg dose - one-third the adult shot - produced antibody levels comparable to those seen in a trial of 16-to 25-year-olds who got the adult dose, the companies said, with similar side effects.

Pfizer and BioNTech said they plan to submit the data as part of a near-term request for emergency-use authorisation from the US Food and Drug Administration (FDA), and to share it with regulators in Europe as well.

A clearance would mark an important new phase of the immunisation campaign in the US, where the Pfizer vaccine already has full approval for people aged 16 and up and is authorised on an emergency basis for those aged 12 to 15.

And a paediatric clearance could arrive as millions of older Americans are receiving additional doses to bolster their initial shots.

The FDA is expected to decide whether to allow a booster shot for the Pfizer-BioNTech vaccine soon. Last Friday, an advisory panel unanimously backed a third dose for people 65 and over, as well as those at high risk of severe complications, after voting against Pfizer's request to authorise boosters for everyone aged 16 and older.

While the FDA often follows its advisers, it is not obliged to, and could still opt to support boosters for a bigger group.

Only certain immunocompromised people are officially permitted to get a third dose on an emergency basis. Initial data from other arms of the Pfizer-BioNTech paediatric trial, testing the vaccine in children under five, could come in the fourth quarter, the firms said.

The data on children from five to 11 was from an initial tranche of patients in the trial. At the request of US regulators, Pfizer and BioNTech plan to add 2,250 more children between the ages of five and 11 to their paediatric studies.

Top FDA vaccine official Peter Marks said he asked drugmakers to expand their paediatric trials three or four times in size "to try to have a larger safety data set" to increase confidence in the shots.

Safety is a vital metric for young children, as they often get infected and help spread the virus but are at lower risk of developing severe complications than older adults.

BLOOMBERG