Pfizer COVID booster may be near
FDA decision due: Some urge shot for all, others say only for vulnerable
Evidence of waning immunity for at least one COVID-19 vaccine may drive federal authorities on Friday to advise older Americans, as well as frontline health care workers, to get a third shot starting as soon as next week.
With the delta variant surging across the United States and public health officials in every state struggling to improve vaccination rates as they wrestle with widespread transmission, pressure is mounting to protect even fully vaccinated people from breakthrough cases that in rare instances result in severe illness or even death.
Pfizer, which makes the vaccine that has been most used in the United States, has requested that its boosters be approved for everyone age 16 and older; an advisory board for the Food and Drug Administration is taking up that request at a meeting Friday. And last month, President Biden said the country should be prepared to
“It’s hard for me to see how the data justify why every American should get a third dose.” Dr. Michael Reid, UCSF Pandemic Initiative for Equity and Action
deliver boosters for all three vaccines to all eligible Americans on Sept. 20.
But many doctors and public health experts have pushed back on that plan, and reports released this week suggest the FDA is more likely to take a nuanced approach and recommend boosters for only select groups of people who are at high risk of severe illness or death or who are very frequently exposed to the virus.
On Wednesday, the FDA released documents it will review at Friday’s meeting, and among them was a report in which federal scientists declined to recommend for or against boosters for everyone. The report noted that current data shows the Pfizer vaccine is still highly effective at preventing severe illness and death among all age groups, and that much of the evidence of waning immunity is inconclusive.
Also on Wednesday, a report out of Israel published in the New England Journal of Medicine provided some of the first real-world evidence that boosters are effective at increasing protection from severe disease as well as mild infections. That study, which involved the Pfizer vaccine and looked at people age 60 and older, found rates of severe illness were about 20 times lower and mild illness about 11 times lower among those who got boosters than those who did not. The FDA is expected to consider that report along with data provided by Pfizer and other studies done in the United States.
All of the reports taken together weave a complex tapestry of data that is difficult to draw conclusions from, say many experts in public health and vaccine immunity. Further complicating the issue is a global vaccine shortage that raises ethical questions about where limited supply should be directed.
“There is data to support boosters. There are certain populations in whom an additional dose is a good thing. But it’s hard for me to see how the data justify why every American should get a third dose,” said Dr. Michael Reid, chief medical officer of the UCSF Pandemic Initiative for Equity and Action.
The FDA for now is scheduled to review and vote on boosters for Pfizer, which is the only one of the three vaccines with full federal approval so far. It likely will consider boosters for the Moderna and Johnson & Johnson vaccines later this year. Pfizer makes up well over half of all vaccines given in the U.S.
If the FDA approves boosters for Pfizer recipients, the topic likely will be taken up by a Centers for Disease Control and Prevention committee that sets national vaccine guidance.
Friday’s public meeting is expected to be lively and potentially heated, and many experts said it wasn’t immediately clear what the advisory board would recommend. For weeks, scientists in favor of boosters for everyone as soon as possible and those who want to wait before offering them widely have staged furious debates in public forums and on social media.
Earlier this week, a group of experts including two FDA scientists published an essay arguing boosters should not be given in the U.S. until more evidence is available and global vaccine equity has been addressed. Dr. Anthony Fauci, the nation’s best known infectious disease expert, has been a vocal proponent of boosters.
Health experts said even before the vaccines were authorized that boosters would likely be needed, either due to waning immunity from the first shots or to keep up with variants. But determining the appropriate time to give boosters is complicated because there are many variables to consider, and decisions must be made under the pressure of a public health crisis.
Ideally the process to consider boosters, and the best schedule for giving them, would take years to work through. “And typically it’s not in the political spotlight where you have the White House and other leaders weighing in,” said Dr. Art Reingold, a UC Berkeley epidemiologist. “But this is an unusual set of circumstances.
“You could argue politicians have gotten a little ahead of themselves,” he said. “But you could counter that this is a pandemic and we don’t have time to waste.”
Indeed, the surge fueled by the highly transmissible delta variant has made the booster question much more urgent, many public health and infectious disease experts say. If the United States had higher vaccination rates and had been able to quell this surge, then it could afford to take more time to assess the need for boosters and who should get them.
But there is so much virus circulating now — especially in the Southern states, but in California and other much more highly vaccinated places as well — that even fully vaccinated people are at greater risk of breakthrough infections. Though vaccinated people are far less likely than unvaccinated people to end up hospitalized with severe illness, those who do tend to be older or suffering from other underlying health problems.
Initial reports showed the Pfizer vaccine was more than 90% effective at preventing hospitalization with COVID-19. Reports released last week by the CDC found that more recently, the rate had dropped to 80%. For all vaccines, protection against hospitalization was lowest — about 76% — for people age 75 and older.
The CDC already has recommended that immune-compromised people get boosters. Advising boosters for older adults, especially those who live in long-term care facilities or other congregate settings, would be a natural next step, many experts say.
Boosters for health care workers also make sense because even though they don’t face great risk of severe illness, hospitals and other facilities can’t afford to lose them for a week or longer if they get even a mild breakthrough infection.
“Right now there’s data that are clear for people age 60 and above, and indirectly frontline health care workers because they’re in touch with all these people who aren’t vaccinated, and also we can’t afford to lose them,” said Dr. Eric Topol, executive vice president of Scripps Research in La Jolla (San Diego County). “Those are the two groups that are pretty clear cut right now.”
Topol and many other experts believe boosters will eventually prove effective for all age groups. But younger adults and teens can probably afford to wait a couple of months to get their third shots, which will give public health officials time to administer boosters to those most in need, as well as collect more data on whether they’re needed for everyone.
“There will be not the same need for everybody to get a booster shot immediately,” said Dr. Melanie Ott, a senior investigator at the Gladstone Institutes in San Francisco. “And, honestly, we would not have this discussion for anyone so urgently right now if we had a 99% vaccination rate, because we would have very little circulating viruses. We would be all protected.”