FDA calls for inclusion of Omicron BA.4/5 in future boosters

Heeding the advice of its expert advisory committee, the US Food and Drug Administration (FDA) on Thursday recommended the inclusion of an Omicron BA.4/5 spike protein component in modified COVID-19 vaccine boosters for the upcoming fall and winter seasons.
 
The recommendation follows a 19-2 vote in favor of adding an Omicron-specific component to future boosters by FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC) earlier this week. (RELATED: VRBPAC recommends addition of Omicron-component to future boosters, Regulatory Focus 28 June 2022)

“As we expect this coming year to be a transitional period when this modified booster vaccine may be introduced, we have not advised manufacturers to change the vaccine for primary vaccination, since a primary series with the FDA-authorized and approved COVID-19 vaccines provides a base of protection against serious outcomes of COVID-19 caused by circulating strains of SARS-CoV-2,” said Peter Marks, director of FDA’s Center for Biologics Evaluation and Research (CBER).
 
Marks added that the goal will be to have the modified vaccines authorized and available by early- to mid-fall 2022.
 
The move is intended to dampen the public health impact of the highly transmissible Omicron variant and its various subvariants, including the BA.4 and BA.5 subvariants, which now account for more than half of US infections, according to data presented during the latest federal data. The decision also comes within the context of waning vaccine effectiveness and vaccine hesitancy, as many vaccinated individuals are now months or more than a year out from receiving their primary series or first booster, and many Americans remain unvaccinated or have not had a booster.
 
Several vaccine makers, including Pfizer and BioNTech, Moderna, and Novavax, are testing modified vaccines that contain a BA.1 component. Marks said that FDA has spoken with the manufacturers who are developing such vaccines and requested clinical data from them before it authorizes an updated vaccine with a BA.4/5 component.
 
During the advisory committee meeting, there was significant discussion about whether a bivalent vaccine should contain a BA.1 component, which is farther from the prototype strain in terms of antigenic cartography, or the BA.4/5 subvariants, which are currently gaining the most ground. Jerry Weir, director of viral products at the Office of Vaccine Research within CBER, pointed out that subvariants are all antigenically distant from the prototype strain.
 
“It’s true on the cartography, BA.1 looks a little farther away, but BA.4/5 is also a ways away on that cartography thing, if you’re just looking at that. It’s also true you have to put that in context: BA.4/5 together, as well as BA.2.12.1 are still much closer to BA.2 than they are to BA.1, which is really nowhere right now … even if you just look at the antigenic cartography, but even if you just look at the antigenic cartography BA.4 is a long way away antigenically from Wuhan Washington, just like BA.1 is,” Weir said.

While the advisory committee members were only asked to vote whether future boosters should contain an Omicron component, most members of the panel indicated that they thought the component should be BA.4/5 based on current trends.
 
FDA