FDA advisors recommend replacing original Covid vaccine with bivalent omicron shots for all doses

The Food and Drug Administration’s independent advisory committee on Thursday recommended replacing Pfizer and Moderna’s original Covid vaccine used in the U.S. for everyone’s first two immunizations with the new bivalent omicron shots.

If the FDA accepts the advisors’ recommendation, the U.S. would likely phase out the companies’ vaccines developed in 2020 against the original Covid-19 strain that emerged in Wuhan, China.

Instead, the drugmakers’ bivalent omicron shots that target the omicron BA.5 subvariant as well as the original strain would be used for the entire vaccination series.

Currently, Pfizer’s and Moderna’s omicron shots are only authorized as a booster, while the first two doses are still their old shots based on the original Covid strain.

The committee’s 21 members unanimously backed the proposal, agreeing that it would simplify the U.S. Covid vaccination program.

“This is absolutely the right thing to do for the program. It will make things simpler,” said Dr. Melinda Wharton, a senior official at the National Center for Immunization and Respiratory Diseases, a division of the Centers for Disease Control and Prevention.

The proposed change would only affect people who have not yet received their two-dose primary vaccination series. No timeline was provided on when this switch might occur if the FDA accepts the panel’s nonbinding recommendation.

The recommendation to adopt a single formulation across all doses comes as the FDA is trying to streamline Covid vaccination so that the system is easier for the public and health-care workers to understand.

“The overall thought here is that getting towards one vaccine composition for everyone will ultimately be much, much more helpful,” said Dr. Peter Marks, who heads the FDA’s vaccine division.

The FDA has proposed moving to a system that resembles how the agency updates and rolls out flu shots every year. The agency would select a Covid vaccine formulation in June to target the variant that is expected to dominate in the fall and winter. That formulation would be used by all manufacturers for all doses.

Under the proposal, most people who have been exposed to the Covid spike protein twice, either through vaccination or infection, would only receive one Covid shot a year moving forward. Older adults and people with compromised immune systems may need two shots because they don’t mount as strong of an immune response.

Marks said the goal is to roll out updated Covid and flu vaccines at the same time in the fall to make it easy for people to get their shots in one visit. This could help boost vaccine coverage and reduce the burden on hospitals as they simultaneously confront circulation of Covid, flu and respiratory syncytial virus, he said.

“The advantage of this also is if we can see the influenza vaccine and the Covid-19 vaccine occurring at the same visit, it facilitates a vaccination program that may lead to more people getting vaccinated and being protected and reducing the amount of disease we see,” Marks told the committee members.

But committee member Dr. Cody Meissner, a pediatrician at the Geisel School of Medicine, said it is too early to say whether annual vaccination for Covid is needed.

Panel member Dr. Paul Offit, a vaccine expert at the Children’s Hospital of Philadelphia, said flu and Covid differ in important ways when it comes to vaccination.

If the flu vaccine doesn’t match the dominant variant, you don’t have much protection, Offit said. But the Covid vaccines are still protecting well against severe illness, he said.

“I think we need to define what we want from this vaccine,” said Offit, who has repeatedly emphasized the prevention of severe disease rather than mild illness.