COVID-19 booster shots are important for some groups of vaccinated people, and recent events have added to confusion about who can and should get them, and when. This article seeks to clarify some of that confusion.
While administering boosters is an important next step in fighting COVID-19, public health experts stress that the disease is spreading largely among those who are unvaccinated. The unvaccinated also are much more likely to be hospitalized and die from COVID-19.
“We don’t want [boosters] to be a distraction from any people who have not had any doses of the vaccine,” said David Lakey, MD, vice chancellor for health affairs and chief medical officer for The University of Texas System and a member of Texas’ Expert Vaccine Allocation Panel, which develops state strategies for distributing vaccines. “That is the primary focus at this time – continuing to encourage people who have not been vaccinated to get vaccinated.”
Why is there so much confusion about COVID-19 booster shots?
The confusion started in part with the way boosters were introduced. In August, President Joe Biden announced most Americans could begin getting boosters of the Pfizer and Moderna vaccines starting Sept. 20 – subject to the regulatory processes at the Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC). In September, FDA considered Pfizer’s application for booster doses. The agency decided there is not enough scientific evidence right now for most adults to receive boosters. It opted instead to authorize the Pfizer booster for certain high-risk populations and essential workers with high exposure. Moderna’s booster application is still under FDA review.
How did the CDC deliberations add to the confusion?
The CDC’s Advisory Committee on Immunization Practices (ACIP) develops recommendations for the routine administration of vaccines. When ACIP recommended eligibility for the Pfizer booster, it excluded essential workers like physicians. ACIP said these workers already have a high degree of protection from the first two doses of Pfizer vaccine. Given that, ACIP decided, there’s not enough evidence to support using limited resources to provide boosters for essential workers as a way to fight the pandemic. But in a highly unusual move, CDC Director Rochelle Walensky, MD, overruled ACIP’s advice and included essential workers in the CDC guidelines for boosters.
Then who should receive a COVID-19 booster?
Broadly speaking, FDA and CDC support a Pfizer booster dose for five groups of people. Everyone in these groups meet two criteria – they received their second dose of Pfizer vaccine at least six months ago and are 18 or older.
Among those people, CDC recommends that three groups should get booster shots:
CDC also allows boosters for two groups of people who may want to get those shots, based on their individual benefits and risks:
- People 18-49 years old with underlying medical conditions; and
- People 18-64 years old who are at increased risk for COVID-19 exposure and transmission because of occupational or institutional setting, namely first responders (physicians, health care professionals and workers, firefighters, police, congregate care staff); education staff (teachers, support staff, day care workers); and workers in food and agriculture, manufacturing, corrections facilities, the U.S. Postal Service, public transit, and grocery stores. This group may be updated in the future, CDC says.
A “third shot” or “additional dose” has been offered for people who have received both Pfizer and Moderna vaccines. Is that a booster?
No. A “third shot” (also known as an additional dose) and a “booster” have different meanings, and the definition of both terms rests on who receives the shot. A third shot is given to people whose immune systems have been moderately or severely compromised, like patients being treated for cancer or who have received an organ transplant, because these individuals probably did not have a strong immune response to the first two shots. Only those who’ve received the first two doses of the Pfizer or Moderna vaccines are eligible for a third shot. A booster is given to people who had a strong immune response to the original two doses but whose immunity could wane over time. So far, only eligible Pfizer vaccine recipients can get a booster.
Can someone who has had a Moderna or Johnson & Johnson shot receive a Pfizer booster?
No. A Pfizer booster dose for Moderna or Johnson & Johnson recipients is not authorized or recommended. FDA and CDC do not recommend mixing COVID-19 vaccines because there is not enough evidence that doing so is safe or effective. People in the recommended groups who got the Moderna or Johnson & Johnson vaccine will likely need a booster shot, CDC says, and more data on the effectiveness and safety of those two booster shots are expected soon.
Is someone still considered “fully vaccinated” without a booster dose?
Yes. Everyone is still considered fully vaccinated two weeks after a second dose of the Pfizer or Moderna vaccines, or two weeks after a single dose of the Johnson & Johnson vaccine. In their discussions, both FDA and CDC stressed that although boosters may be recommended for some populations as a proactive step to prevent possible waning immunity, most fully vaccinated people – no matter which vaccine they received – still have high protection against hospitalization and death. People with questions about underlying medical conditions that may affect their risk of COVID-19 should consult their physician.
Can kids receive a booster dose if they have an underlying condition?
No. The FDA booster authorization covers only people at least 18 years old. The data considered did not include those under 18, so FDA did not feel it could safely include this group. Currently, children aged 12 to 17 are eligible to receive their first two doses of the Pfizer vaccine. The Moderna and Johnson & Johnson vaccines currently are recommended only for those 18 and older.
What do I do if someone ineligible approaches me for a booster shot?
Remind them about the eligibility requirements for those who can and cannot receive booster shots. Also point out physicians who agree to administer COVID-19 vaccines sign an agreement stipulating they will administer the shots according to FDA and CDC recommendations.