WASHINGTON – U.S. health experts are expected to recommend COVID-19 booster shots for all Americans eight months after they get their second dose of the vaccine, to ensure longer-lasting protection as the delta variant spreads across the country.
Federal health officials have been looking at whether extra shots for the vaccinated would be needed as early as this fall, reviewing case numbers in the U.S. as well as the situation in other countries such as Israel, where preliminary studies suggest the vaccine’s protection against serious illness dropped among those vaccinated in January.
An announcement on the U.S. booster recommendation is expected as soon as this week, according to two people familiar with the matter who spoke to The Associated Press on the condition of anonymity to discuss internal deliberations.
Doses would only begin to be administered widely once the Food and Drug Administration formally approves the vaccines, which are being dispensed for now under what is known as emergency use authorization. Full approval of the Pfizer shot is expected in the coming weeks.
Last week, U.S. health officials recommended boosters for some people with weakened immune systems, such as cancer patients and organ transplant recipients, citing their higher risk of catching the virus and evidence that the vaccines' effectiveness wanes over time.
The director of the National Institutes of Health, Dr. Francis Collins, said Sunday the U.S. could decide in the next couple of weeks whether to offer booster shots to Americans this fall.
Among the first to receive them could be health care workers, nursing home residents and other older Americans, who were some of the first to be vaccinated once the shots were authorized last December.
Since then, more than 198 million Americans have received at least one dose of a COVID-19 vaccine, according to the Centers for Disease Control and Prevention, with more than 168 million fully vaccinated.
Still, the country is experiencing a fourth surge of virus cases as a result of the more contagious delta variant, which is spreading aggressively through unvaccinated communities but is also responsible for an increasing number of “breakthrough infections” of fully vaccinated people.
Israel, which exclusively administered the Pfizer shot, has been offering a booster to people over 60 who were vaccinated more than five months ago in an effort to control its own surge in cases of the delta variant.
On Tuesday, European medical regulators said they are talking with vaccine developers about the need for boosters but haven’t made any decisions.
On Monday, Pfizer and its partner BioNTech announced they submitted data to the FDA to support authorizing a booster shot for the general public. Pfizer said a small study showed people who received a third dose had higher levels of antibodies against several strains of the coronavirus, including the delta variant. The company is working on a larger study, the results of which will soon be submitted to regulators.
Studies show the shot remains highly protective against severe COVID-19, but results released last month suggested the effect wanes about six months after the second dose. Its effectiveness against symptomatic infection dropped gradually, from a peak of 96% two months after study participants got their second dose. Four months later, it was down to 90%, and by six months, it was about 84%.
Americans who received the earliest doses of Pfizer's vaccine — mainly health care workers and nursing home residents — are approaching the eight-month mark from when they received their second dose.
“There is a concern that the vaccine may start to wane in its effectiveness,” the NIH's Collins said. “And delta is a nasty one for us to try to deal with. The combination of those two means we may need boosters, maybe beginning first with health care providers, as well as people in nursing homes, and then gradually moving forward” with others.
He said because the variant only started hitting the country hard in July, the next couple of weeks of case data will help the U.S. make a decision.
The Pfizer and Moderna vaccines are administered in two doses. Officials are continuing to collect information as well about the one-shot Johnson & Johnson vaccine, which was only approved in the U.S. in late February, to determine when to recommend boosters.
The White House has said that even though the U.S. has begun sharing more than 110 million vaccine doses with the world, the nation has enough to deliver boosters to Americans.
Global health officials, including the World Health Organization, have called on wealthier and more-vaccinated countries to hold off on booster shots to ensure the supply of first doses for people in the developing world.