Will COVID vaccine boosters be necessary? Here's what you need to know.

Sara Omar, age 13, is inoculated by Nurse Karen Pagliaro at Hartford Healthcare's mass vaccination center at the Connecticut Convention Center in Hartford, Connecticut on May 13, 2021.

Sara Omar, age 13, is inoculated by Nurse Karen Pagliaro at Hartford Healthcare's mass vaccination center at the Connecticut Convention Center in Hartford, Connecticut on May 13, 2021.

Joseph Prezioso / Getty Images

The first round of the COVID vaccination program continues amid a return to normal, but some Connecticut health experts say booster shots will become part of the future to keep the disease at bay.

It’s common for some vaccines to require booster shots to keep the body immune to diseases, experts say. But how that will play out for the COVID-19 vaccine, rapidly developed and deployed during a yearlong pandemic, remains a topic of discussion.

Top U.S. health officials in recent weeks have said booster shots may be required to address mutations in the virus over time.

“The bottom line is, we don't know if or when we will need booster shots,” Dr. Anthony Fauci, the White House’s chief medical advisor, told NBC News last week. “But it would be foolish not to prepare for the eventuality that we might need it.”

While Connecticut continues to be a leader in vaccine administration, there are still many people who have not received a dose. State and health officials continue to push ahead to get more people vaccinated while the virus continues to circulate among residents.

Here are answers to some of the questions about boosters:

Will there be a need for boosters?

At least two Connecticut health experts said they anticipate the need for a COVID vaccine booster, and say it will be useful for multiple reasons. For one, a booster could address some of the COVID variants that have been popping up globally, said Dr. Ulysses Wu, system director of infectious disease, chief epidemiologist and chief anti-microbial steward at Hartford HealthCare.

“Viruses mutate,” Wu said. “That’s normal. That’s always going to happen. Should a virus mutate, then we would have to get a booster to handle that mutation.”

In addition, he said, immunity to viruses — whether from a vaccine or antibodies produced during an infection — usually fades over time, making a booster shot necessary.

Steven Valassis, chairman of emergency medicine at St. Vincent's Medical Center in Bridgeport, which is part of Hartford HealthCare, agreed that boosters will likely be necessary — and health care workers will likely be among the first who will need them.

“Most of us were vaccinated in December or January,” he said. “I suspect we’re going to need a booster shot to protect us.”

Are booster shots being developed for the COVID-19 vaccine?

There are three vaccines approved by the U.S. Food and Drug Administration for emergency use against the COVID-19 virus: Pfizer-BioNTech, Moderna and Johnson & Johnson.

Pfizer-BioNTech, the first to receive government approval, has been studying since early this year whether a booster shot, or potentially a third dose of the vaccine, would be needed in the future. It takes two shots right now to get the full benefits of the Pfizer vaccine.

Moderna similarly has been studying boosters for its two-dose vaccine. This month, the company announced positive results from its booster trials.

Johnson & Johnson’s CEO Alex Gorsky told CNN in March that the company was working on a booster for its vaccine as well.

Johnson & Johnson and Pfizer-BioNTech have not released results from any trials on vaccine boosters.

Will there be demand for boosters?

Health experts are unsure whether people will sign up for a booster. Valassis said the success of the state’s vaccination program should indicate to people that the shots are an effective way to prevent COVID.

“Connecticut has done such a great job vaccinating people and we can see the benefits of that,” he said. “I hope that is a good motivation for people to get a booster shot, so we can continue on that trajectory to herd immunity.”

But Wu said it’s possible that the state could be a victim of its own vaccination success. “The more people get a vaccination, the less you see of the disease,“ he said. “The less you see of the disease, the less willing you are to see it as a problem.”

Though he hopes there’s a good response to any boosters that come out, Wu is somewhat skeptical.

“I think there’s going to be less people who get it compared to the original vaccination rollout,” he said.

Do many other vaccines require boosters?

Booster shots are common in the course of vaccines administered to children and adults, though not all vaccines require one.

Many vaccines require boosters to maintain their efficiency, including tetanus, measles, mumps and rubella, and many other illnesses people are first vaccinated against as children, Wu said.

The most common vaccine that requires a booster is for tetanus, diphtheria, and pertussis, which happens every 10 years, according to the Centers for Disease Control and Prevention.

While not a booster, the flu shot is administered annually to address prevalent strains of the virus circulating across the globe.

Other vaccines are given in spaced out courses to children and adults to gain full effect.