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Booster shots for all adults six months after being vaccinated against Covid-19 are safe, effective, and badly needed. The United Kingdom and the European Union have authorized them for all adults. Israel won’t let anyone enter the country without one.

In the U.S., however, the FDA authorized a booster dose of the Pfizer/BioNTech Covid-19 vaccine only for individuals over age 65, those who face elevated risk due to their health conditions, or who work in jobs that put them at higher risk of infection.

In imposing these limits, the FDA overstepped its role for vaccine approvals.


The FDA fully approved the Pfizer vaccine — granting it a biologics license application — in August. The FDA’s role in approving the Pfizer Covid-19 booster is to review safety and efficacy. Its job does not include balancing “public” costs against benefits, nor deciding who gets priority to receive vaccines. Congress assigned the Centers for Disease Control and Prevention as the lead agency for public health policy for infectious diseases with input from the National Institutes of Health.

The safety of the Pfizer Covid-19 booster is similar to the first two doses. Millions of booster shots have been delivered, in the U.S. and elsewhere. There is no increased risk for myocarditis (an inflammation of the heart muscle that is the most important side effect) with a third dose versus a second, and that risk is meaningful only for young men. Even for them, however, the risk is very low and vastly outweighed by the risks of Covid-19 infection.


The FDA recognized this safety profile when it authorized booster shots for those in “at risk” groups.

The evidence for effectiveness is still emerging, but what is known today is ample. Results from Israel indicate that a booster dose greatly lowers the risk of severe illness. Boosters also prevent infection. This reduces the spread of SARS-CoV-2 among vaccinated and unvaccinated individuals. It isn’t yet clear how long protection from boosters will last, but the world can’t wait to find out. The waning effectiveness seen in multiple studies in Israel, in the U.S., and elsewhere implies that serious illness and death among recipients of the Pfizer vaccine will increase without boosters.

The evidence that booster shots are needed is overwhelming. Israel provides the best data because it vaccinated its populace with the Pfizer vaccine early and has excellent population data. Six months after vaccination, the country saw sharply lower protection against infection. A major booster campaign turned the tide against a surge in infections, hospitalization, and death due to the highly infectious Delta variant.

The risk of Covid-19-related hospitalization, which was near zero soon after vaccination, has also risen sharply — up tenfold since early this year. The roughly 98% protection found early on is now down to 77% in one recent study, and low- to mid-80s in others.

The FDA, in judging who most needs a booster, is arrogating powers it does not have. If approval for those over 65 is a “no-brainer,” as the FDA’s top vaccine official, Peter Marks stated, and reduces the Covid-19 risk for them and health care workers, so too for everyone else. Safety is the same. Efficacy is the same. Younger people face lower absolute risk from Covid-19 but deciding on vaccine priority is not the FDA’s role.

The FDA is a science agency, not a policy agency. It is required by law to approve a booster shot if it is safe (this is not in reasonable dispute) and effective, a threshold normally satisfied by being non-inferior to the original, approved vaccine (also not in dispute). As Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, told Kaiser Health News, “there’s very little doubt that the boosters will be beneficial. The Israelis already have that data in spades. They boost, they get an increase by tenfold in the protection against infection and severe disease.”

Limited access to boosters means more infections, hospitalizations, and deaths. The Covid-19-related death rate in the U.S., already at the top of the scale among advanced economies, will rise further. The economy will underperform as people stay home due to fear of infection.

There are also less obvious consequences. Millions of people are getting boosters by claiming to be eligible or simply not disclosing prior vaccination. This “self-help” will often be among the well-educated and well-informed, and thus will increase the large disparities in Covid-19 sickness and death seen so far in the U.S. Moreover, measuring how many people were vaccinated once, twice, or thrice will become a guessing game.

The reputation of U.S. regulatory agencies, already diminished by prior Covid-19 missteps, will drop further. People who want booster shots will hear: “The government wants to keep me from getting a booster. Other countries can get boosters, but not us.”

Early this year, when the vaccine supply was limited, most Americans accepted the need to give priority to the elderly and health care workers. Not so when the message is, “We have ample vaccine supplies but won’t give them to you.”

There is another way. The FDA should authorize the Pfizer booster for all adults aged 18 years and older six months after initial vaccination, and should do the same for the Moderna and J&J boosters. These stand in a different regulatory posture, due to the FDA’s slowness in granting full approval. But the FDA’s expertise is still in science, not public health policy. The need for a Moderna booster is lower than for Pfizer, due to slower decline in efficacy against infection. But people who received the less-effective J&J vaccine have especially strong need for a booster, which significantly improves efficacy.

There is also increasing evidence supporting mixing and matching vaccines. This should be allowed, as it is in the U.K. Recipients of the J&J vaccine should be able to get a Pfizer or Moderna booster, yet the FDA has punted on this issue.

The FDA can’t cure many Americans’ reluctance to get vaccinated. But it should stay in its own regulatory lane and get out of the way of the majority of vaccinated Americans who, informed by guidance from the CDC and medical advice, can make their own decisions on getting a booster, how soon, and which one.

Bernard Black is professor of law and finance at Northwestern University. David Thaw is professor of computing & information and law at the University of Pittsburgh. Both have extensively studied the Covid-19 pandemic.

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