Biden’s administration health officials increasingly think vulnerable populations will need revaccinations, even as research continues on how long coronavirus vaccines remain effective.
Senior officials now say they expect people 65 or older or those with weakened immune systems will likely need a third shot from Pfizer-BioNTech or Moderna, two vaccines based on the same technology used to inject the suppressive most Americans for now. This is a dramatic shift from what was just a few weeks ago, when the administration said it thought there was not enough evidence to support boosters yet.
A key Centers for Disease Control and Prevention official said Thursday that the agency is exploring options for providing immunocompromised patients with third doses even before regulators extend the emergency use of coronavirus vaccines, which could happen soon for the Pfizer Vaccine.
Dr. Amanda Cohn, chief physician of the CDC’s immunization department, told the agency’s advisory committee that officials are “actively looking for ways” to provide some people with access to booster vaccinations “before any possible change in regulatory decisions.”
“So stay tuned,” she added.
The growing consensus within the administration that at least some Americans will need revaccinations is partly due to studies suggesting that the Pfizer vaccine is less effective against the coronavirus after about six months. More than half of the fully vaccinated in the United States have so far received the Pfizer vaccine in two doses given three weeks apart.
According to the company, an ongoing global study of Pfizer’s clinical trial participants shows that four to six months after the second dose, the vaccine’s effectiveness against symptomatic infection declines from 95% to 84%.
Data from the Israeli government, which has fully vaccinated more than half of its population with doses of Pfizer since January, also indicates a downward trend in efficacy over time, although administration officials are wary of the data due to the large number of errors.
According to the latest figures from the Israeli Ministry of Health released later this week, the Pfizer vaccine was only 39% effective in preventing infection in that country in late June and early July, up from 95% between January and April.
The vaccine remained over 90% effective in preventing serious illness and nearly as effective in preventing hospitalization. On July 12, Israel began offering a third dose of Pfizer to citizens with severely weakened immune systems.
In the US, Dr. Anthony Fauci, head of the infectious diseases department at the National Institutes of Health, said he was surprised by the apparent sharp drop in the effectiveness of the Pfizer vaccine, which the Israeli seems to be suggesting. He said he wants to compare this with data the CDC has collected from cohorts of thousands of people across the United States. “People raise their eyebrows a little,” he said.
Despite many other questions, senior administration officials said it is becoming increasingly clear that vaccines will not provide permanent immunity against the virus and that boosters may be needed by at least some people, perhaps nine months after their first vaccination. The administration has already purchased more than enough vaccine to deliver third doses of Pfizer and Moderna, and is quietly preparing to scale up distribution efforts if the need arises.
With so little data that has yet to be published, many health officials and experts are cautious about revaccinations. Dr. Paul Offit, FDA External Expert Advisory Committee on Vaccines, said mild to moderate cases are on the rise. COVID-19 among vaccinated people did not necessarily mean revaccination was needed.
“The purpose of this vaccine is not to prevent mild to moderate infectious disease,” he said. “The goal is to prevent hospitalization to death. Right now, this vaccine has withstood it. “
Other health experts warn that early deviation from the prospect of a third dose could also act as a deterrent against vaccinations. If Americans think immunity from vaccines is short-lived, they are less likely to receive their first vaccine, they said.
“We don’t want people to believe that when you talk about boosters, it means vaccines are ineffective,” Fauci said at a congressional hearing on Tuesday. “They are very effective.”
Among vaccine manufacturers, Pfizer is particularly active in sharing its data with the government. But the administration was taken aback by the company’s public announcement this month that it plans to request an emergency clearance from the FDA for a second injection.
The company said early data from its booster study showed that the levels of neutralizing antibodies among clinical trial participants who received the third dose six months after the second were 5-10 times higher than those who received two doses.
Fearing that the American public would misunderstand the message, the FDA and CDC responded with an unusual public statement: “Americans who have been fully vaccinated do not need booster vaccinations at this time.” They added: “We are ready for booster doses if and when science shows that they are needed.”
Usually the FDA will approve the use of the booster, possibly after an external advisory committee meeting. Then the CDC, which has its own advisory committee, will have to formally recommend it, Offit said.
But if the FDA issues a full license for the vaccine, doctors will have much more leeway to prescribe booster vaccinations for their patients. Some health experts expect Pfizer to get this approval by the fall.
At a CDC advisory group meeting on Thursday, Cohn, a medical officer for the vaccine division, suggested that booster vaccinations could be offered to people with weakened immune systems through research or other means, without waiting for the FDA.
Dr. Camilla Cotton, an infectious disease expert at Massachusetts General Hospital, told the group that some patients, especially those who are more educated or “empowered to take care of their own health,” manage to get a third dose. own, despite the lack of a green light from the government.
“A lot of people took matters into their own hands,” she said. “It worries me that they are doing this unattended,” she said, while doctors’ hands are tied due to lack of regulatory approval.
According to the CDC, people with weakened immune systems make up 2.7% of the population, including people with crayfish, organ or stem cell transplants, or HIV, among other conditions.
At a Senate Health Committee hearing on Tuesday, several senators asked health administration officials how soon they would take action on the booster issue. Senator Mitt Romney, Rhode Utah, said he was unhappy that officials were unable to provide a better timetable.
Senator Richard Burr, RN.C., noted that Israel is already offering some of its most vulnerable citizens a third chance. Why don’t we make the same decisions? he asked.
Dr. Rochelle Walenski, director of the CDC, testified that scientists have studied the effectiveness of vaccines in tens of thousands of people, including residents of nursing homes and more than 5,000 key workers.
“Fortunately, we expect these to subside rather than abruptly,” she said of their effectiveness. “When we see this decrease … it will be our time to act.”
Pfizer is expected to soon publish the results of its clinical study on immunosuppression and the benefits of booster vaccination in peer-reviewed journal articles. Moderna has yet to release data on any booster studies.
Johnson & Johnson’s disposable vaccine has so far played a secondary role in the national vaccination campaign. Clinical trial data on how this vaccine works with two shots is expected next month.