Many coronavirus vaccination sites are making it easy for people to shop for the vaccine they want.

Why it matters: Public health officials have advised for months that the best vaccine to get is the one that's first available. But giving people a choice about which shot to get could help improve overall vaccination rates, especially among more hesitant Americans.

By the numbers: Johnson & Johnson's one-shot vaccine is particularly popular with people who say they want to wait and see how the vaccine is working for others before getting it, according to recent KFF polling.

• Among Americans open to getting vaccinated, only 28% said they had a strong preference of which shot they want, and nearly half said they didn't have a preference.
• Similar shares said they would "definitely" get each of the three vaccines authorized for use in the U.S., although J&J had a slight edge over Pfizer and Moderna's two-dose vaccines.
• Among those with a brand preference, about a quarter said they prefer a single-dose vaccine.

Where it stands: Vaccine Finder, a website that helps people find open vaccine appointments, allows people to select which vaccines they want to search for. The site is operated by Boston Children’s Hospital and supported by the Centers for Disease Control and Prevention.

• Federally run mass vaccination sites also often publicize which vaccine they're offering.

Zoom in: CVS lists which vaccine is being offered at all of its locations administering shots.

• "We want people to know what they’ll be receiving, and prepare accordingly.  This of course means being aware of booster shot requirements for Pfizer and Moderna vaccines (which are booked at the same time as the first shot)," CVS spokesperson T.J. Crawford said.
• CVS doesn't think giving people this information will impact those still waiting for a vaccine, Crawford said. "Appointments are filled fast across the board, including where we’ve offered the Johnson & Johnson vaccine. Based on what we’ve seen, people do believe 'the best vaccine is the one available.'"
• Publix administers both the Moderna and Johnson & Johnson vaccines, but offers specific "booking opportunities" for each throughout the week. In Florida, for example, it administers Moderna on weekdays and J&J on weekends, and people sign up a few days ahead of time.

What they're saying: Giving people the option to sign up for the vaccine they want has its tradeoffs. On the one hand, it could increase overall vaccine uptake.

• It could also help overcome certain barriers to getting vaccinated for certain populations. For example, people who have a hard time getting off of work or who are afraid of needles may prefer the J&J shot, said Tara Kirk Sell, an assistant professor at the Johns Hopkins Center for Health Security.
• But if people delay getting vaccinated to wait for the shot they want, that could be a bad thing. “With cases rising and variants circulating, this is not the time to delay," said Ashish Jha, dean of the Brown University School of Public Health.

The bottom line: “I do think you could end up with a line [for one vaccine] versus not on the other," Kirk Sell said. "But at the end of the day though, I respect people’s ability to make choices, and that’s certainly part of this as well.”