Facing the threat of a more infectious Delta variant, vaccine makers Pfizer and BioNTech released a statement on Thursday saying it “may be beneficial” for people to get a third dose of their COVID vaccine within six months to a year. But US health officials and other scientists have vehemently disagreed, saying our current vaccines are holding up really well — at least so far.
“Americans who have been fully vaccinated do not need a booster shot at this time,” reads an unusual joint statement from the FDA and the CDC released hours after Pfizer’s announcement. “People who are fully vaccinated are protected from severe disease and death, including from the variants currently circulating in the country such as Delta.”
Holding off on a booster is reasonable, scientists told BuzzFeed News, both because our vaccines are still holding off infections against current variants and because even in the rare cases when vaccinated people do get infected, they’re protected against severe disease and death.
“The dam is still holding, even if there has been some splashing going on,” said immunologist E. John Wherry, director of the Penn Institute of Immunology.
The strength of the vaccines, paired with the fact that Delta has rapidly become the dominant strain of the virus circulating in the US, only increases the urgency that more people get fully vaccinated, health officials said. In some parts of the US, more than 80% of new COVID-19 cases are Delta, and it is linked to surges in the UK and Africa, with a surge feared for Europe by August.
“Preliminary data from several states over the last few months suggest that 99.5% of deaths from COVID-19 in the United States were in unvaccinated people,” said CDC chief Rochelle Walensky on Thursday. “Those deaths were preventable with a simple, safe shot.”
Clinical trials of the mRNA vaccines last year reported a stunningly good, roughly 95% rate of preventing infections by the original coronavirus strain. While recent studies of the effectiveness of Pfizer’s two-shot mRNA vaccine against the Delta variant in the United Kingdom and Canada have shown a slight dip in the protection the shots offer, two doses still reduce the risk of infections by 79% to 88%. Israel’s health authority announced unpublished results in May suggesting protection against Delta was lowered to 64%, but even then, the shots were 93% effective at preventing severe disease and death.
Even the one-shot Johnson & Johnson vaccine, authorized in the US but used more rarely, offers reasonably good protection against Delta, said Anthony Fauci, chief of the National Institutes of Allergy and Infectious Diseases, during a Thursday White House briefing. He added that the vaccine still lowers the risk of hospitalization by 93%.
“If you had told any of us that’s the effectiveness we have now with vaccines a year ago, we would have run to have taken that deal,” said Wherry. “We’re talking about a very substantial effectiveness rate that could have a major impact on restraining the pandemic.”
Fauci and other experts stressed the emergence of more contagious variants as just one more reason for the 32% of American adults still unvaccinated to get their shots. “Please get vaccinated. It will protect you against the surging of the Delta variant,” said Fauci.
Variant Time Bomb
Still, as long as the virus is replicating in people, it will mutate and give rise to new strains, said immunologist Andrew Pekosz of the Johns Hopkins Bloomberg School of Public Health.
Some of those strains have mutations that make them more infectious. The Delta strain, for example, is roughly 2.5 times more likely to infect unvaccinated people under age 50. And those mutations can also make the viruses less recognizable to our immune systems, which have been trained by vaccines to target the original coronavirus.
The newest variant raising concern is Lambda, flagged by the World Health Organization as a “variant of interest” in June. While a preliminary study in Chile suggests that, like some other variants, it lowers the effectiveness of vaccines, more studies are needed.
“The problem is the variants that we don’t know of, and where would those be generated,” said Jerome Kim, director of the International Vaccine Institute, a nonprofit focused on global vaccine development based in South Korea. “The risk is that if we continue to allow significant portions of the globe to be unvaccinated, then we are putting ourselves and all of our investments and time at risk, really undermining a year’s worth of really intense scientific effort.”
That presents yet another argument against delivering booster shots to people so soon, since those shots could be used to deliver vaccines to those who are still unvaccinated. Even ignoring humanitarian concerns, getting vaccines out to the rest of the world is the best way to stop the emergence of variants that could threaten everyone.