By Thomas M. Burton

WASHINGTON -- There will likely be enough evidence by late fall this year to potentially extend the use of Covid-19 vaccines to many children under age 12, Biden administration health officials told a U.S. Senate panel Tuesday.

"We expect to have data on the safety and effectiveness of vaccines for children under 12" by that time, David Kessler, the administration's chief Covid-19 scientific officer, told the Senate Committee on Health, Education, Labor and Pensions.

Administration medical adviser Anthony Fauci told the panel that such steps to vaccinate younger children will probably occur in stages, progressing younger and younger, as study evidence accumulates.

The testimony occurred a day after the Food and Drug Administration greenlighted the use of a Covid-19 vaccine from Pfizer Inc. and BioNTech SE in youngsters 12 through 15. That vaccine was authorized late last year by the FDA for broad use in adults from age 16 and older.

It also followed last week's decision by the Biden administration to support the temporary waiver of intellectual property provisions to allow developing nations to produce Covid-19 vaccines created by pharmaceutical companies, citing the need to stop the virus's spread globally.

Sen. Richard Burr (R., N.C.), the committee's ranking Republican, criticized that decision, calling on the U.S. to "let the private sector continue" its impressive performance on vaccines so far.

Dr. Kessler acknowledged that "a waiver alone won't result in the scale and speed" of vaccine production needed to end the global pandemic.

To combat Covid-19 around the world, the Biden administration has just redirected a U.S. order of AstraZeneca vaccine manufacturing supplies to India, which will allow that nation to make over 20 million doses of vaccine, Dr. Kessler said. The U.S. is also delivering supplies to help supply medical oxygen for patients in India, he said, as the pandemic there rages largely out of control.

The Senate hearing covered a swath of Covid-19 topics. Rochelle Walensky, director of the federal Centers for Disease Control and Prevention, testified that despite the widespread U.S. vaccination campaign, continued mask-wearing, social distancing and other fundamental public-health measures still are necessary to avoid Covid-19 variants that could spread much more quickly than the original virus.

While the U.S. vaccination campaign has had considerable success, she said, "available data suggest that antibodies elicited by vaccination with the currently authorized vaccines are able to neutralize the [U.K.] B.1.1.7 variant but have reduced neutralization" against those first identified in South Africa and Brazil.

Peter Marks, the director of the FDA's center that evaluates vaccines, said the agency continues to consider whether to license a troubled vaccine plant in Baltimore run by Emergent BioSolutions Inc. The facility made about 110 million total doses of Johnson & Johnson vaccine and AstraZeneca PLC vaccine.

The doses, about 60 million from AstraZeneca and the remainder from Johnson & Johnson, can't be used until the FDA signs off on safety of the plant.

Dr. Marks said those doses already manufactured "will undergo additional testing and will be thoroughly evaluated to ensure their quality before any potential distribution."

Write to Thomas M. Burton at tom.burton@wsj.com

(END) Dow Jones Newswires

05-11-21 1432ET