While many Americans are trying to move on with their lives after two years of the COVID-19 pandemic, U.S. health officials are debating the best way to use vaccines to stay ahead of the coronavirus.

What You Need To Know

  • Members of the FDA's Vaccines and Related Biological Products Advisory Committee met Wednesday to discuss key questions for future COVID-19 booster campaigns

  • Dr. Peter Marks last week said it wouldn’t be surprising if the agency authorized another booster dose in the fall to protect most Americans against the latest coronavirus mutations

  • COVID-19 cases have dropped to low levels in the U.S., but health officials are warily watching an omicron sibling that now accounts for most cases

  • The panel heard presentations from government health officials and independent researchers that underscored the challenges of predicting what the virus will do

A panel of U.S. vaccine experts met Wednesday to discuss key questions for future COVID-19 booster campaigns. The Food and Drug Administration’s vaccine advisers won’t make any binding decisions, but they could help shape the government’s approach for years to come.

FDA vaccine chief Dr. Peter Marks told reporters last week that it wouldn’t be surprising if the agency authorized another booster dose in the fall to protect most Americans against the latest coronavirus mutations. He opened Wednesday’s meeting by cautioning that waning vaccine protection, new variants and colder weather later this year could raise the risk of more surges.

“All that taken together makes us conclude that a general discussion of booster vaccination against COVID-19 is warranted at this time so that we can potentially intervene,” Marks said.

Another concern is that the American population will get worn out from too many booster shots, he added.

“What really keeps me up at night is the knowledge that we can’t keep boosting and that we only — we’re gonna have vaccine exhaustion," Marks said. "And I’m not talking about immune exhaustion, I’m talking about physical exhaustion of people not going to get boosted."

The panel heard presentations from government health officials and independent researchers that underscored the challenges of predicting what the virus will do.

Trevor Bedford, a disease modeler with the Fred Hutchinson Cancer Research Center, said a major new strain like omicron could emerge anywhere from every 1.5 years to once a decade, based on currently available data. Given that unpredictability, researchers will need methods to quickly determine whether current vaccines work against emerging variants.

Last week, the FDA authorized an extra Pfizer or Moderna shot for anyone 50 or older and for some younger people with severely weakened immune systems. It’s an effort to get ahead of another possible surge.

Only about half of Americans eligible for a third shot have gotten one. And some independent experts disagree about the need for even that additional protection in healthy individuals, due to limited evidence of the benefit or how long it might last.

The FDA has based many booster decisions on data from the Israeli government, which began offering a fourth dose to people 60 and older in January.

COVID-19 cases have dropped to low levels in the U.S., but health officials are warily watching an omicron sibling that now accounts for most cases.

Early data on that effort published this week showed that the fourth dose significantly lowered rates of severe disease. But protection against any infection faded fast, with little evidence of a benefit for people who received a fourth dose after several weeks.

The last U.S. wave was driven by the omicron variant. During that surge, two vaccine doses were nearly 80% effective against needing a breathing machine or death — and a booster pushed that protection to 94%, federal scientists have reported.

COVID-19 cases have dropped to low levels in the U.S., but health officials are warily watching an omicron sibling that now accounts for most cases.

All the COVID-19 vaccines now used in the U.S. are based on the original coronavirus version that emerged in late 2019. Updating the vaccines will be a complex task, requiring coordination between the FDA, manufacturers and global health authorities.

In response to panel questions, a representative for the U.S. Biomedical Advanced Research and Development Authority laid out the narrow window that manufacturers would face to reformulate, study and mass produce an updated vaccine by September.

“If you’re not on your way to a clinical trial by the beginning of May I think it’s going to be very difficult to have enough product across manufacturers to meet demand,” said Robert Johnson, deputy assistant secretary of BARDA.

The timeline for updating annual flu vaccines offers one possible model, and the FDA panel discussed the strengths and weakness of adopting such an approach.

Twice a year, World Health Organization experts recommend updates to flu vaccines to target emerging strains. The FDA then brings those recommendations to its own vaccine panel, which votes on whether they make sense for the U.S., setting the stage for manufacturers to tweak their shots and begin mass production.

But COVID-19 hasn’t yet fallen into a predictable pattern like the flu. Dr. Marks acknowledged such an approach for COVID-19 vaccines offers a "poor person's correlate of protection," as antibody levels have not been established in the same way as those for the flu. And vaccine manufacturers will likely need more time to conduct additional studies of their COVID-19 vaccines, which don’t have the same decades-long record of safety and effectiveness as flu shots.

The discussion came as the White House continues to press Congress to approve additional COVID-19 funding beyond the $10 billion bipartisan agreement reached earlier this week, in part saying that the United States is not prepared to vaccinate the population should a variant-specific vaccine become necessary. 

“If the science shows that fourth doses are needed for the general population later this year, we will not have the supply necessary to ensure shots are available, free and easy to access, for all Americans,” Zients said. “Without more funding, we can't procure the necessary vaccine supply to support shots for all Americans.”

“Furthermore, if things change, and there's a need for a new vaccine, a new formulation, for example, a variant-specific vaccine, we won't be able to secure doses for the American people, and we won't be able to ensure America is first in line for them,” Jeff Zients, White House coronavirus response coordinator, told reporters in late March, calling the possibility “completely unacceptable.” 

While around $750 million of the $10 billion will go towards researching emerging coronavirus variants and potential vaccine manufacturing expansions, addressing Zients' concerns in part, the bill does not include funding for global vaccination campaigns, which members of the Biden administration have stressed as imperative in stopping the emergence and spread of new variants around the world.