The Food and Drug Administration’s independent advisory committee on Thursday recommended replacing the original Pfizer and Moderna Covid vaccine, which is used for everyone’s first two shots in the United States, with the new Omicron bivalent vaccines.
If the FDA accepts the advisers’ recommendation, the US 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, targeting both the BA.5 subvariant of Omicron and the original strain, would be used for the entire vaccine series.
Currently, Pfizer and Moderna’s Omicron shots are only approved as a booster, while the first two doses are still their old shots based on the original Covid strain.
The 21 members of the committee unanimously supported the proposal and agreed that it would simplify the US Covid vaccination program.
“This is absolutely right for the program. It will make things easier,” 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 series. No timeline was given for when that switch might occur if the FDA accepts the panel’s non-binding recommendation.
The recommendation to adopt a single formulation for all doses comes as the FDA seeks to streamline Covid vaccination so the system is easier for the public and health workers to understand.
“The general thought here is that eventually it will be much, much more helpful to get to one vaccine composition for everyone,” said Dr. Peter Marks, who heads the FDA’s vaccine division.
The FDA has proposed moving to a system similar to how the agency updates and rolls out flu shots each year. The agency would select a Covid vaccine formulation in June to target the variant expected to dominate in the autumn and winter. This formulation would be used by all manufacturers for all dosages.
Under the proposal, most people who have been twice exposed to the Covid spike protein, either through vaccination or infection, would only receive one Covid vaccination per year going forward. Older adults and people with compromised immune systems may need two shots because they don’t have as strong an immune response.
Marks said the aim is to launch simultaneously updated Covid and flu vaccines in the autumn to make it easier for people to get their shots in one visit. This could help increase vaccination coverage and ease the burden on hospitals as they confront the spread of Covid, the flu and respiratory syncytial virus at the same time, he said.
“Also the benefit of this is if we can see the influenza vaccine and the Covid-19 vaccine occurring in the same visit, it facilitates a vaccination program that can lead to more people being vaccinated and protected and the number of diseases that we see is reduced,” Marks told committee members.
But committee member Dr. Cody Meissner, a pediatrician at the Geisel School of Medicine, said it was too early to say whether annual vaccination against Covid would be necessary.
The board member Dr. Paul Offit, a vaccines expert at 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 still protect well against serious diseases, he said.
“I think we need to define what we want from this vaccine,” said Offit, who has repeatedly emphasized prevention of serious illness rather than mild illness.