External advisers to the Food and Drug Administration met last month to discuss two key questions on coronavirus boosters: Should all vaccine shots be switched to the newer bivalent formulation, and should boosters be administered yearly along with doses of the flu vaccine?
On the first question, the advisers decided that switching to the bivalent version was best for both. The updated booster elicits a better antibody response against omicron variants compared with the original. Real-world studies confirm this, and recent data from the Centers for Disease Control and Prevention provide reassurance that the booster works against the now-dominant XBB.1.5 subvariant.
Before the advisers’ decision, only after people received both doses of the original vaccines were they able to get the updated booster. This complicated operations because pharmacies had to stock both formulations. With the revised protocol, most people who haven’t received the updated vaccine, including previously unvaccinated individuals, would be offered one bivalent dose. Because this results in both better protection and more streamlined operations, FDA advisers voted unanimously in favor of the single formulation.
The question of switching to an annual booster schedule, however, was a far more contentious issue. The advisers did not vote on it; if they did, it would have probably been a split decision.
The Biden administration has already staked out its position: In September, Ashish Jha, the White House covid-19 response coordinator, laid out a proposal for the coronavirus booster to be timed with the yearly flu shot. “I really believe this is why God gave us two arms — one for the flu shot and the other one for the covid shot,” Jha said at the time.
The FDA agreed, suggesting in its briefing documents to advisers a strategy that follows the influenza playbook. Every June, scientists would predict which strains are likely to circulate in the winter, and manufacturers would develop variant-specific vaccines in time for a mass vaccination campaign in the fall.
Such a booster plan has many benefits. As I’ve previously written, there is a well-established protocol for yearly influenza vaccines, and piggybacking on that would lessen the burden on already-strained public health systems.
Also, a combined coronavirus-flu campaign could increase uptake. Only about 15 percent of eligible Americans have received a bivalent booster shot, while more than half of children and 46 percent of adults have received a shot of this season’s flu vaccine. On a population level, it would be a success to increase coronavirus vaccine coverage to that of the flu vaccine.
The major downside is that research doesn’t back a one-size-fits-all solution. The protection afforded by the booster will probably wane well before the year is up. Effectiveness against infection may start declining within a few months, so people at high risk for severe outcomes might need boosters more often. On the other hand, most children and healthy adults who have been exposed to the coronavirus through vaccination, infection or both are unlikely to become severely ill, so an annual booster is probably unnecessary for them.
I believe there is a way to reconcile this conflict, and it begins with the FDA implementing its proposal of predicting strains and synchronizing coronavirus boosters with the flu vaccine. It could even come up with a combined coronavirus and flu vaccine to further streamline processes.
Then, every fall, the CDC should partner with local and state health departments and providers to launch a vaccination campaign focusing on getting the most vulnerable individuals inoculated. This should include nursing home residents, the immunocompromised and elderly individuals with multiple medical conditions.
Getting the updated vaccine to these groups will have the greatest societal benefit by reducing the strain on hospitals ahead of future “triple-demics” of flu, respiratory syncytial virus (RSV) and the coronavirus. In the meantime, the new booster can be made available to the general population for people to take at their optimal moment. Some might wish to delay the booster until a few weeks before holiday gatherings or major trips. Others who recently contracted covid might postpone their shot to later in the winter.
Those who are particularly anxious about the coronavirus should also have the option to be boosted more than once a year. Others might decide that they no longer wish to avoid covid and don’t want the temporary benefit of the additional booster at all. It would be a mistake to require annual boosters for healthy young people, just as it would to limit more frequent administrations to the elderly who desire more protection.
As the Biden administration ends its national emergency for covid, the booster discussion is emblematic of how Americans should think about mitigation measures: Protective mechanisms are essential for some and a choice for most. Government policies should focus on optimizing vaccines and treatments for the vulnerable while allowing others to decide their level of protection.