In a contentious discussion about booster dosages, Israeli researchers claimed on Wednesday that a third dose of the Pfizer-BioNTech coronavirus vaccine can protect persons over 60 for at least 12 days from infections and severe sickness.
The study, which was published in the New England Journal of Medicine, is the latest salvo in the debate over whether booster doses are necessary for healthy adults and whether they should be given out, as the Biden administration intends, while so much of the world is still unvaccinated.
Several independent scientists believe that based on current evidence, only older adults will require boosters and that they may not even be required.
According to specialists, vaccination remains a powerfully protective factor against severe illness and hospitalization in the vast majority of people in all studies reported thus far. The immunizations, however, appear to be less effective against infections in people of all ages, especially those who have been exposed to the extremely contagious Delta strain.
The Israeli results demonstrate that a booster can improve protection in older persons for a few weeks – a result that experts say is unsurprising and does not indicate a long-term advantage.
“What I expect to happen is that the immune response to that booster would increase, then contract,” Marion Pepper, an immunologist at the University of Washington in Seattle, said. “However, is that three- to four-month window what we’re aiming for?”
Officials from the Department of Health and Human Services, including Dr. Anthony S. Fauci, President Biden’s top medical adviser on the pandemic, have defended plans to administer booster shots by citing new evidence from Israel and other nations indicating vaccine immunity fades with time.
Some Americans are rushing to get booster shots even before they are legally allowed, which the FDA might do as soon as Friday. The concept has been met with scepticism and outrage even among government scientists.
Two scientists in charge of the Food and Drug Administration’s vaccination branch announced their departure this fall, citing their dissatisfaction with the administration’s drive for booster shots before federal experts could assess the evidence.
A multinational group of experts, including the leaving FDA officials, denounced the drive for boosters on Monday. The scientists evaluated dozens of research in their study, which was published in The Lancet, and determined that using vaccine doses to protect the billions of people who are still unvaccinated would be better for the globe.
“Our primary goal here in this pandemic was, first and foremost, to avoid, to end all preventable deaths,” said Dr. Soumya Swaminathan, World Health Organization chief scientist and co-author of The Lancet review. “And, given that we have the tools to do so very effectively, we should be using them to save lives all over the world.”
To prevent the virus from mutating into even more dangerous forms than the Delta variant — and possibly into one that evades the immune response entirely — experts say the more pressing need is to protect the unvaccinated, both in the United States and elsewhere.
The World Health Organization has asked world leaders to hold off on distributing boosters at least until the end of the year, to immunize 40% of the global population. However, some high-income countries have already begun to provide boosters to their citizens, and others may follow suit.
On Tuesday, British scientists recommended that adults over the age of 50 and other medically vulnerable people in the country receive the third dose. France, Germany, Denmark, and Spain are also considering or have begun administering boosters to older adults. Israel has authorized boosters for anyone over the age of 12 and is already considering fourth doses for its citizens.
Based on the health records of more than 1.1 million people over the age of 60, the Israeli team collected data on the effect of booster shots for the new study. The researchers discovered that at least 12 days after the booster, rates of infection were elevenfold lower and rates of severe disease nearly twentyfold lower in those who had received a booster compared to those who had only received two doses.
The researchers admitted that their findings were preliminary. “At this point, we cannot predict what will happen in the long run,” said Micha Mandel, a statistics and data science professor at the Hebrew University of Jerusalem.