The possibility of covid-19 booster shots for all is looking less and less likely to happen in the U.S., at least for the time being. Scientists in the U.S. and elsewhere have argued that the general public does not need boosters currently, given the continued protection that vaccines appear to provide against illness, hospitalisation, and death. Meanwhile, there continue to be reported tensions within the Biden administration about the booster plan set to be enacted later this month, which could be scaled down to only cover people over 65 and some health care workers.
In mid-August, the White House announced its intention to sanction booster shots for all Americans who took a two-dose mRNA vaccine. The plan was to begin the week of September 20, and the booster would be recommended for everyone eight months after their second shot. Those who took the Johnson & Johnson vaccine were told a similar recommendation would likely happen for them as well, once more data emerged.
The heads of the Food and Drug Administration and Centres for Disease Control and Prevention endorsed the idea, but, as the Biden announcement noted, any booster plan would need formal permission from the FDA and CDC. The plan and the September timeline, however, were not warmly welcomed by some of the staff at these agencies.
Two weeks later, two of the FDA’s top officials involved in vaccine approval — Marion Gruber and Phil Krause — abruptly announced their retirement by early October. Soon after, Endpoints News reported that these departures were due to long-simmering tensions with the CDC, as well as their current frustration with the White House in promising booster doses to the public before it was really clear that such a plan was needed. And on Monday, a group of U.S. and international scientists, including both Gruber and Krause, published a review article in the Lancet, concluding that boosters aren’t necessary for the general population right now. Though these vaccines are generally safe, pushing people to get an unneeded third dose could further increase the risk of rare adverse events like myocarditis (heart inflammation), they add.
The FDA told the New York Times that the article only represents the view of the authors, not the agency, and that its deliberations on booster doses are still ongoing. Yesterday, Politico also reported on infighting between the White House, FDA, and CDC, including anonymously sourced allegations hurled against the CDC that it’s not being speedy enough in handing over data relevant to evaluating the need for booster shots.
The booster debate isn’t helped by the fact that there’s plenty of conflicting evidence floating around. Some data from Israel, for instance, has suggested that vaccine effectiveness against infection has begun to substantially drop off, both due to the emergence of the Delta variant and a large decline in antibody levels over time. Research from other countries has reaffirmed a drop in protection against infection, but at least some data hasn’t found a large drop off in effectiveness against symptomatic infection (in other words, actually getting sick) from Delta. Most data continues to show highly effective protection against hospitalisation and death.
Beyond that, the review authors argue that a focus on boosters will sap resources away from the more impactful strategy of getting people their first doses. Despite supply pledges from the U.S. and other countries, as well as ongoing negotiations over vaccine patents, it will take until at least next year before a large majority of the global population is vaccinated, particularly people living in poorer countries. The World Health Organisation has pleaded with wealthy countries to hold off on boosters for this exact reason.
Booster shots are likely to be needed for all at some point, many experts have said. But there does seem to be stronger evidence that certain vulnerable people could noticeably benefit from extra doses right now. In the U.S., many immunocompromised people are now recommended to receive a third dose of an mRNA vaccine as part of their standard schedule. Data from Israel and some from the U.S. has suggested that older people are experiencing more waning immunity against hospitalisation — data that compelled Israel to start boosters for residents over 60, though it has since expanded eligibility to the general population. Officials and experts affiliated with the CDC have recently signalled that they may agree to approve a booster dose for those over the age of 65, as well as for frontline health care workers.
At this point, it’s unclear how the U.S. booster plan will pan out. But one important factor will emerge on Friday, when the FDA’s advisory committee is scheduled to discuss the issue. Their votes will likely play a pivotal role in determining the ins and outs of any booster strategy.