The U.S. Food and Drug Administration on Monday authorized updated COVID-19 vaccines from Pfizer/BioNTech and Moderna that target a recently circulating Omicron variant of the coronavirus, paving the way for the launch later this week of a fall vaccination campaign.
A third shot, made by Novavax, is still under review by the FDA. Novavax said it did not expect its shot to be authorized in the United States before a meeting of a Centers for Disease Control and Prevention advisory panel on Tuesday to recommend who should receive the updated vaccines.
Shares of Novavax closed down around 13% at $7.82.
Pfizer and Moderna said their updated vaccines, which target the XBB.1.5 subvariant of the virus, were expected to be available for most people in the United States in the coming days. The FDA approved those shots for people ages 12 and above, and authorized them for emergency use in children ages 6 months through 11 years.
"The public can be assured that these updated vaccines have met the agency's rigorous scientific standards for safety, effectiveness and manufacturing quality," top FDA scientist Dr. Peter Marks said in a statement. "We very much encourage those who are eligible to consider getting vaccinated."
An endorsement by CDC Director Mandy Cohen, expected in the coming days, should clear the way for the new shots. Cohen has said she expects the shots to roll out in September.
The FDA authorization follows a late summer rise in cases at a time the new EG.5 subvariant of Omicron - nicknamed Eris - has begun to rapidly spread in the United States and other countries. Scientists also have raised concerns about the highly mutated BA.2.86 subvariant detected in several countries.
Pfizer and Moderna said last week that their updated COVID-19 vaccines generated strong responses in testing against BA.2.86. Novavax is still working to see how effective its vaccine is against the subvariant, the company's Chief Executive John Jacobs said in an interview.
Jacobs said Novavax anticipates U.S. authorization of its vaccine in the near term.
"We're working with them. We don't control their particular timing, but we're moving rapidly," Jacobs said, noting that the company has produced tens of millions of doses of its new shot and signed contracts for broad distribution across the country.
The company is still planning on presenting at Tuesday's meeting of CDC advisers and does not believe that an additional meeting would be required for the CDC to sign off on its vaccine once it is approved.
Novavax's protein-based vaccine is based on an older technology than the messenger RNA vaccine, which has been used for decades to combat diseases.
"It would be nice to have a complete approval on it (Novavax's shot). But obviously that requires that FDA have decided the data supports it," said Jesse Goodman, a professor at Georgetown University and former FDA chief scientist.