Several panelists said on Friday that they felt comfortable with the amount of data the N.I.H. researchers had gathered to recommend F.D.A. authorization for mixing vaccines. Dr. Ofer Levy, director of the Precision Vaccines Program at the Boston Children’s Hospital at Harvard, said that many Americans had already taken the matter into their own hands, and he urged the F.D.A. to step in.
“In the real world, all these kinds of combinations or extra boosters are already happening, so I think it’s a matter of some urgency for F.D.A. to help sort out what is admittedly a complicated and challenging scenario,” he said. “We can’t hide from it. And I do think we need to give guidance to the public.”
What to Know About Covid-19 Booster Shots
The F.D.A. authorized booster shots for a select group of people who received their second doses of the Pfizer-BioNTech vaccine at least six months before. That group includes: vaccine recipients who are 65 or older or who live in long-term care facilities; adults who are at high risk of severe Covid-19 because of an underlying medical condition; health care workers and others whose jobs put them at risk. People with weakened immune systems are eligible for a third dose of either Pfizer or Moderna four weeks after the second shot.
The C.D.C. has said the conditions that qualify a person for a booster shot include: hypertension and heart disease; diabetes or obesity; cancer or blood disorders; weakened immune system; chronic lung, kidney or liver disease; dementia and certain disabilities. Pregnant women and current and former smokers are also eligible.
The F.D.A. authorized boosters for workers whose jobs put them at high risk of exposure to potentially infectious people. The C.D.C. says that group includes: emergency medical workers; education workers; food and agriculture workers; manufacturing workers; corrections workers; U.S. Postal Service workers; public transit workers; grocery store workers.
For now, it is not recommended. Pfizer vaccine recipients are advised to get a Pfizer booster shot, and Moderna and Johnson & Johnson recipients should wait until booster doses from those manufacturers are approved. The F.D.A. is planning to allow Americans to receive a different vaccine as a booster from the one they initially received. The “mix and match” approach could be approved once boosters for Moderna and Johnson & Johnson recipients are authorized.
Yes. The C.D.C. says the Covid vaccine may be administered without regard to the timing of other vaccines, and many pharmacy sites are allowing people to schedule a flu shot at the same time as a booster dose.
Dr. Amanda Cohn, a C.D.C. official, said that the F.D.A. could perhaps include general language in its authorizations of the vaccines that would allow for combinations.
“From a public health perspective, there’s a clear need in some situations for individuals to receive a different vaccine,” she said.
The N.I.H. trial looked only at antibody levels, which on their own are an insufficient measure of how well different combinations would protect people. Dr. Lyke said studies on immune cell responses were underway.
Referring to the limited data on mixing and matching, Dr. Johan Van Hoof, a Johnson & Johnson executive, said a booster was preferable. “These findings are important,” he said of the study, “but only a piece of the puzzle, and they don’t give the complete picture.”
Even so, some experts said the evidence was still pointing to switching vaccine platforms.
“At the end of the day, folks having the Johnson & Johnson should probably get an mRNA booster,” said Scott Hensley, an immunologist at the University of Pennsylvania. “It’s just a matter of how much data does the F.D.A. need before making that recommendation?
“I wouldn’t want to be in their shoes,” he added.
Todd Gregory contributed reporting.