Vaccine boosters could soon be available for some. Here's what you should know.

More Connecticut residents may be able to benefit from an increased rollout in booster shots as early as this week, as some of the country’s top health agencies are expected to release updated guidance in the coming days.

While some health officials are split over the science behind additional doses, especially for the general population, the booster shot for vaccinated Americans has been backed by President Joe Biden’s administration.

Here’s what you need to know:

Do any vaccines have booster shots available yet?

The Food and Drug Administration has not yet granted approval to booster shots for most Americans - but that may change by the end of this week.

An FDA advisory committee voted last week to recommend emergency use of the third Pfizer-BioNTech shots for high-risk Americans and those older than 65. This could prompt the FDA to authorize the booster shots for eligible individuals who received the Pfizer vaccine later this week.

Once the FDA does approve the booster shots, the Connecticut Department of Public Health has said it could begin administering booster vaccines as early as Sept. 24 to Pfizer recipients.

Meanwhile, DPH is awaiting further recommendations for booster doses for the Moderna and Johnson & Johnson vaccines in the coming weeks. Johnson & Johnson said Monday that a second dose of their one-dose vaccine provides 94 percent protection against the virus. An added booster shot would increase the vaccine's protective strength against COVID-19, the company said in a statement, signaling a potential push to boost third-dose rollout in the coming months.

What is the latest guidance from the state?

While administration of third doses to immunocompromised individuals can proceed as planned, DPH has cautioned state vaccine providers to hold off on booster shot implementation until after the Center for Disease Control and Prevention’s Advisory Committee for Immunization Practices meets and makes further recommendations for booster shots. The ACIP is scheduled to meet later this week to deliberate broader rollout guidelines.

Earlier this week, DPH said it was closely monitoring federal guidance around the booster shot rollout following the FDA committee’s unanimous recommendation for emergency use authorization of Pfizer’s booster dose.

And Gov. Ned Lamont said last week the state was prepared to offer boosters to nursing home patients once it received the go-ahead by federal agencies to do so.

Who can get a COVID-19 booster shot?

There are still narrow eligibility constraints for hopeful third-dose recipients.

The FDA advisory committee specifically recommended the third shot of Pfizer only for Americans ages 65 and older and those who are at higher risk of contracting a severe case of COVID-19.

DPH currently lists only immunocompromised individuals as eligible for the third shot. That definition includes those who: are receiving active cancer treatment, have received an organ transplant and are taking medicine to suppress their immune system, received a stem cell transplant within the last two years, have moderate or severe primary immunodeficiency, have advanced or untreated HIV infection, or receive active treatment with high-dose corticosteroids or other drugs that suppress immune response.

Expanded eligibility will likely be announced at the end of this week, according to health officials.

How many people have already received a third dose?

The state has administered 19,400 third doses as of last week, according to Chris Boyle, a spokesperson for the state Department of Public Health. Those doses went to immunocompromised individuals, in line with federal guidance.

Nationwide, the CDC said more than two million people have already received a third shot.

When should you receive a booster?

People can receive third doses beginning 28 days after their last dose. According to DPH, individuals will be eligible for a booster shot starting eight months after their second dose of either Pfizer or Moderna vaccines.

The CDC and FDA will issue similar guidance on potential J&J booster shots in the coming weeks.

Where can you receive a shot?

According to DPH, if you are eligible for a third dose, you can receive the vaccine through your healthcare provider, a vaccine clinic, or participating pharmacies.

Does the state have enough vaccine availability for the booster shot?

Yes. Multiple health officials have said the state has supplies on hand and the ability to get more weekly once the booster is available. But they are requiring appointments once the shot is initially authorized for widespread roll out.

What is the latest guidance for young children and vaccination?

Pfizer announced Monday that a clinical trial had shown its vaccine is safe and generated an antibody response in children ages 5-11. Pfizer will reportedly seek emergency use authorization from the FDA. That agency could then authorize a vaccine for young children in a few weeks.

The Pfizer vaccine is already available for children older than 12.