U.S. experts are struggling with how to upgrade the vaccine against COVID-19

WASHINGTON (AP) – More than two years after the COVID-19 pandemic, U.S. health officials are beginning to struggle with how to update vaccines to best protect Americans from the ever-changing coronavirus.

On Wednesday, a group of vaccine consultants at the Food and Drug Administration spent hours discussing key issues for rebuilding vaccinations and conducting future reinforcement campaigns. They did not come to any solid conclusions.

Experts were faced with questions: how often to update vaccines against new strains, how effective they should be for approval and whether to coordinate updates with global health authorities.

Last week, the FDA approved the introduction of the fourth dose of Pfizer or Moderna vaccines for all people over the age of 50 and for some young people with severely weakened immune systems. This is an attempt to anticipate another possible surge.

But FDA vaccine chief Dr. Peter Marx admitted at the meeting that “we just can’t stimulate people as often as we do.” He called the latest reinforcement update a “shut-off” measure to protect vulnerable Americans, while regulators decide whether and how to set up current vaccines.

Marx warned that reduced protection of vaccines, new options and colder weather in the fall could increase the risk of new jumps.

“Our goal here is to anticipate future options and outbreaks and ensure that we do our best to reduce the number of diseases and deaths due to COVID-19,” Marx said, adding that he expects more meetings of the vaccine group in the coming months. .

Some of the key issues discussed in the panel:


One area in which experts seem to agree is that vaccines should be evaluated for their ability to prevent serious diseases that lead to hospitalization and death.

“We need to focus on the worst case, which is a serious illness, and we need to change strains if we lose this battle,” said Dr. Mark Sawyer of the University of California, San Diego.

Accordingly, current vaccines are holding up perfectly.

During the latest surge caused by omicron, two doses of the vaccine were nearly 80% effective against the need for a breathing machine or death – and the booster raised that protection to 94%, federal scientists recently reported.

But only about half of Americans eligible for the third degree received it. And many experts said continuing to ask Americans for Americans to receive incentives every few months was unprofitable.

An expert from the Centers for Disease Control and Prevention suggested that 80% protection against serious diseases could become the standard for evaluating vaccines.

“I think we may have to take that level of protection and then use other alternative ways to protect people through therapeutic and other measures,” said Dr. Amanda Cohn, CDC chief physician.

Reports at a meeting of government health officials and independent researchers highlighted the challenge of predicting when the next major version of COVID-19 may appear.

Trevor Bedford, a disease developer with the Fred Hutchinson Cancer Research Center, said a new major strain, such as omicron, could appear anywhere from 1.5 years to once a decade, based on available data. Given this unpredictability, researchers will need techniques to quickly determine whether current vaccines work against new options.


All three COVID-19 vaccines currently in use in the United States are based on the original version against coronavirus, which appeared in late 2019. Upgrading vaccines will be a challenging task that is likely to require coordination between the FDA, manufacturers and global health authorities.

To accelerate the release of vaccines, the FDA relied on research labels to judge efficacy, largely by looking at their early effects on immune system antibody levels. A number of panelists said Wednesday they want to get more rigorous data from studies that track patients over time to see who is sick or dying.

But such an approach is likely to take too much time.

“We’re looking for a puzzle here that it will be difficult to create all the necessary data in a short amount of time when a new option comes along,” said Dr. Ofer Levy of Harvard Medical School.

A spokesman for the U.S. Office of Advanced Biomedical Research and Development has laid out a narrow window that manufacturers may face to reformulate, study and mass-produce an updated vaccine by September.

“If you’re not on your way to clinical trials by early May, I think it will be very difficult to have enough products for all manufacturers to meet demand,” said Robert Johnson, BARDA’s deputy assistant secretary.

The process of updating annual influenza vaccines offers one of the possible models outlined by a representative of the World Health Organization.

Twice a year, WHO experts recommend updating flu vaccines to target new strains. The FDA then transfers these recommendations to its own group of vaccines, which votes on whether they make sense for the U.S. by creating the ground for manufacturers to set up their injections and start mass production.

But COVID-19 has not yet fallen into such a predictable scheme as the flu. And as the coronavirus develops, different strains may become dominant in different regions of the world.

Several experts said they would need more meetings with more data and suggestions from the FDA to decide on the strategy.

“We have never been here before. We’re all working together to do our best, and it’s very challenging, ”said Oveta Fuller of the University of Michigan Medical School.


The Associated Press Department of Health and Science receives support from the Department of Science Education of the Howard Hughes Medical Institute. AP is solely responsible for all content.

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