Now that federal regulators have cleared booster shots of all three coronavirus vaccines in use in the United States, state health authorities and pharmacies have begun rolling out plans to get even more shots in arms.

Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, on Thursday recommended Moderna and Johnson & Johnson boosters for tens of millions of Americans, a move that came nearly a month after many Pfizer-BioNTech recipients were cleared for boosters of that company’s vaccine.

The CDC also gave a green light to a “mix-and-match” strategy so people eligible for boosters can decide to get a dose of a different type than the one they first received.

And as states, pharmacies and doctors Friday began trying to get these shots into arms, they faced a variety of complex issues — they will have to help people understand whether they are eligible and answer questions about which booster to get.

According to the CDC, certain groups of people who received their second dose of an mRNA vaccine six or more months ago are now eligible for a booster. Those who qualify are people 65 and older, those 18 and older who live in long-term care, and those who have underlying medical conditions, or work or live in settings placing them at high risk of infection. For those who received the single-shot J&J vaccine, anyone 18 and older who was vaccinated two or more months ago is eligible. The Moderna booster, whether people originally got that company’s vaccine or either of the other two, will be a half-dose shot.

Limited evidence strongly suggests that booster doses of one of the two mRNA vaccines — Moderna and Pfizer-BioNTech — more effectively raise antibody levels than a booster dose of the J&J vaccine.


“Now, with 10 months of vaccine experience, some may have an express preference for one booster type over another,” Walensky said Friday, referring to the mix-and-match option, adding that it was “perfectly fine” for people to choose a booster of the same vaccine that they received initially.

Other challenges medical providers will contend with include reaching marginalized groups, such as homeless people and migrant workers, who may have received the J&J vaccine when it was only meant as a single-dose option, and making sure that people receive the correct dose of a Moderna booster.

More than 120 million Americans will become eligible for a booster in the coming months, Jeffrey Zients, the White House coronavirus response coordinator, said at a news conference Friday, adding that boosters are available at more than 80,000 locations across the country, including at least 40,000 local pharmacies. CVS and Walgreens said they expanded their booster offerings Friday and were able to provide mix-and-match doses.

State health departments generally follow the recommendations of the CDC, and many were prepared to begin moving ahead with boosters.

On Friday, Colorado Gov. Jared Polis got a Moderna booster, after receiving his second Moderna shot six months earlier. Polis, 46, said he was eligible because his job puts him at high risk of exposure.

“Like most Coloradans and Americans, I am ready to put this pandemic behind us,” Polis said from behind a medical mask, adding. “I am excited to get this level of protection.”


Maryland Gov. Larry Hogan welcomed the CDC’s guidance on Friday, saying in a statement, “Eligible Marylanders may now choose which vaccine they want for a booster, even if it is different from what they received initially.” Officials said the state had been preparing for the decision for months, with more than 300 sites available since last month, including large and small pharmacies, hospitals, urgent care centers and mobile vaccination operations.

Vermont Gov. Phil Scott announced that eligible residents could receive the new boosters beginning Friday.

In Oregon, the state health department has enrolled hundreds of providers to administer boosters, and will train them on giving different amounts of doses, according to Kristen Dillon, a senior adviser to the state’s COVID response-and-recovery unit.

Officials in New Jersey said they would open several state mass vaccination sites to handle the expected demand, in addition to offering shots at schools, pharmacies and large county sites.