TAMPA, Fla. (WFLA) — If you’re eligible for a COVID-19 vaccine booster shot, you have three choices – but which one is best for you?

Right now, seniors and younger adults at high risk due to a job or health condition are eligible for a COVID-19 booster shot. You can get the shot six months after completing the Pfizer or Moderna regimen and two months after getting the Johnson & Johnson vaccine.  

The Food and Drug Administration allows for mixing and matching vaccines but federal regulators haven’t said whether doing that is beneficial. Experts who spoke with 8 On Your Side said, in some instances, mixing shots is preferable.

“There’s a logical advantage to mix in some cases and not in others,” Moffitt Cancer Center’s Chief of Infectious Diseases Dr. John Greene explained. “If you got the J&J vaccine, the best outcome for you is to get either a Pfizer or Moderna vaccine.”

Why? A small study from the National Institutes of Health showed J&J recipients had more antibodies after getting a Moderna or Pfizer booster.

“Probably makes some sense,” Dr. Jason W. Wilson with Tampa General Hospital said. “If that’s a Pfizer vaccine, that’s a full-dose Pfizer vaccine. If that’s a Moderna vaccine, that’ll be half the dose of Modnera.”

But what if you originally had Pfizer or Moderna – one of the Messenger RNA (mRNA) vaccines?

“There’s no way for me to tell you which is better to do,” Dr. Wilson said. “We don’t have that level of data.”

Dr. Greene agreed.

“My preference is to stick with the same one you had,” Dr. Greene said.

For now, experts say, stick with your original mRNA vaccine unless you had a complication.

8 On Your Side asked Dr. Greene about the real-world implications of a study that showed those who received Moderna had a higher antibody response than Pfizer.

“Is there any evidence that the Moderna booster is going to give us better protection or longer protection?” Investigative reporter Mahsa Saeidi asked.

“There is a study that shows because the Moderna was a higher dosage, it was causing the immune system to stay up higher and longer than the Pfizer,” Dr. Greene explained. “However, there is no proof that one is necessarily dramatically better than the other, they’re pretty much equivalent.”

Dr. Wilson says approximately 190 million people are vaccinated in the United States currently.

“We need to make sure we keep focus around getting other people even beginning the series of vaccination,” Dr. Wilson said. “Then becomes the conversation about the booster doses.”

He says that people who have the original series of vaccination have nine to 15 times the protection against hospitalization.

Experts say it’s rare but different vaccines have different possible side-effects. For example, if you’re a young man with a history of inflammation of the heart, you may opt to get a J&J booster.

As always, experts say you should talk with your doctor about the COVID-19 vaccine and any boosters. They know your health history and may have a recommendation.