This browser does not support the Video element.
After an advisory panel for the U.S. Food and Drug Administration voted to reject a plan to offer a booster dose of Pfizer-BioNTech’s COVID-19 vaccine for Americans, two top health officials in the country believe the use of booster shots may be expanded "in the next few weeks."
Dr. Francis Collins, the National Institutes of Health director, said the panel’s decision was a preliminary step and predicts broader approval is likely for most Americans.
Collins told "FOX News Sunday" that the panel’s recommendation Friday was correct based on a "snapshot" of available data on the effectiveness of Pfizer’s two-shot regimen over time. But he said real-time data from the U.S. and Israel continue to come in showing waning efficacy among broader groups of people that will need to be addressed soon.
Collins, who also appeared on CBS’ "Face the Nation," said: "I think there will be a decision in the coming weeks to extend boosters beyond the list that they approved on Friday."
On Friday, the panel voted to endorse COVID-19 booster shots only for Americans 65 and over, and for those who are at high risk for severe disease.
RELATED: FDA advisory panel OKs Pfizer COVID-19 booster for 65 and older, votes no for younger
Dr. Anthony Fauci, who is President Joe Biden’s chief medical adviser, on Sunday praised the advisory board’s plan for covering a "good chunk" of Americans. But he stressed that "this is not the end of the story" based on evolving data and said the recommendations will likely be expanded in the coming weeks to months.
The FDA will consider the advisory group’s advice and make its own decision, probably within days. The Centers for Disease Control and Prevention also is set to weigh in this week.
The panel said Friday after voting that more data was needed to determine if boosters are safe and effective.
The vote by the committee of outside experts assembled by the FDA was 16-12, with members expressing frustration that Pfizer had provided little data on the safety of extra doses. Many also raised doubts about the value of mass boosters, rather than ones targeted to specific groups.
Panel members also complained that data provided by Israeli researchers about their booster campaign might not be suitable for predicting the U.S. experience.
U.S. health officials are urgently looking to shore up Americans’ protection against the virus amid the highly contagious delta variant, which has fueled U.S. COVID-19 cases and deaths to levels not seen since last winter.
RELATED: CDC report: One third of COVID-19 patients report long-term symptoms
The U.S. has already approved an extra dose of both the Pfizer or Moderna vaccines to people who are immunocompromised, or those with severely weakened immune systems.
Separate FDA and CDC decisions will be needed in order for people who received the Moderna or J&J shots to get boosters. It’s not clear how soon that could come.
This story was reported from Detroit. The Associated Press contributed.