The U.S. government looks set to tell most everyone to get a booster shot against covid-19 sooner rather than later. Late Monday, the New York Times reported that officials will issue a blanket recommendation as early as this week for people who received either the Pfizer/BioNTech or Moderna vaccine to get a third dose of the same brand eight months after their last shot. The expected change in policy comes as the country is battling yet another resurgence of the pandemic, this one fuelled by the Delta variant.
The NYT cited anonymous sources within the Biden administration in reporting this new development, though other reports have indicated that these plans have been in the works for weeks. According to the NYT, the announcement may be made by federal officials this week, but it will depend on further authorization from the Food and Drug Administration. Assuming things go well, the first officially authorised booster shots could start going out to health care workers and others who received the initial batch of vaccines last winter as early as mid-September.
The expected decision follows a recommendation made last week by health agencies for certain groups of immunocompromised people to receive a third dose. Evidence has consistently shown that these individuals tend to develop weaker immunity to the coronavirus from their initial vaccination, compared to the general public, and that their immune response often improves after a third shot (for these individuals, a third dose may need to be standard practice). The evidence for the need of a booster shot for everyone else is less certain, but not absent.
Data from Israel, for instance, has suggested that their first vaccine recipients late last year are starting to experience waning immunity in general, though not all scientists agree with this interpretation. Other evidence has found that the widely spread and highly contagious Delta variant is more likely to cause breakthrough infections than past strains, dashing hopes that the mRNA vaccines would offer near-complete protection from infection and subsequent transmission. Even highly vaccinated countries have experienced recent Delta-led surges of the pandemic, while more than 80,000 Americans are currently hospitalized with covid-19. There is also some preliminary evidence from Israel that older vaccinated people may experience waning protection from severe illness caused by the virus, but most data has indicated that vaccinated people continue to have a substantially lower risk of hospitalisation and death than the unvaccinated and unexposed.
The booster dose plan isn’t expected to cover those who have received the single-dose Johnson & Johnson shot, at least not until data from ongoing trials of a two-dose strategy of that vaccine is made available to analyse. But while research has shown that the J&J shot (or the similar AstraZeneca/Oxford vaccine) continues to provide strong protection from death even in the face of Delta, other data has suggested that boosting with a mRNA vaccine strengthens a person’s immune response. The city of San Francisco already now allows anyone who received the J&J vaccine to get a mRNA booster. Overall, around 13 million Americans have gotten the J&J shot, compared to 155 million fully vaccinated with an mRNA vaccine, according to a CDC tracker.
The World Health Organisation has pleaded with countries to hold off on boosting their residents until more of the world has been vaccinated even with first doses. Currently, only around 23% of the world has been fully vaccinated, and only 1.3% of people in low-income countries have received even one dose. Unchecked spread of the virus in parts of the world with low vaccination rates could result in the evolution of virus strain that can fully evade vaccine immunity, experts including Anthony Fauci have warned.
Though the WHO has called for a moratorium on booster shots until at least the end of September, Israel has already begun distributing booster doses, while several countries in the EU and likely now the U.S. have announced plans to start booster shots by next month. There is some early data from Israel suggesting that these booster doses may indeed be providing added protection from the virus.
Even before this expected announcement, many vaccinated Americans were already getting in on the booster action. According to reportedly leaked documents from the Centres for Disease Control and Prevention, described by ABC News last week, over one million Americans have already gotten unauthorised booster shots, not counting those who received the J&J shot. While many Americans may be eager for additional shots, though, the spread of the pandemic, especially in the U.S., continues to be driven by the unvaccinated.