SALT LAKE CITY, Utah (ABC4) – Could a booster shot be needed for the COVID-19 vaccine? The answer isn’t clear yet, but local health experts explain why other vaccines that people get often need more than one jab.

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“You have your tetanus shot that they say you need a booster every 10 years. We know enough about that, that every 10 years you should receive another Tdap vaccine,” said Leslie Stulce, an infection prevention coordinator for MountainStar Healthcare.

Booster shots are given to build strong immunity over time, if protection wears off or the virus mutates.

“That will either make those memory cells work again or work against a different variant of the disease,” Stulce said.

Research has shown that additional doses of vaccine train a person’s body to recognize the virus or bacteria and defend itself.

“Your body then creates antibodies that create cells that remember this virus, so the next time you’re exposed to it, it can help fight it so you don’t get as sick,” she said.

Dr. Andrew Pavia, the chief of pediatric infectious diseases at the University of Utah and director of epidemiology at Intermountain Primary Children’s Hospital, explains how researchers determine if a vaccine needs a booster.

“The first, you watch over time how well the protection from a vaccine is working. Right now, the vaccine is protecting people 6-8 months out and about 90-95 percent effectiveness – which is remarkable,” he said.

There’s speculation a COVID-19 booster shot may be needed but that’s still uncertain right now.

As scientists continue to understand the virus, they’ll learn more about how long immunity will last.

“I think it’s likely some form of boosting is going to be needed. But we have no idea if it will be every year, every other year, every third year, until we have the data,” Pavia said.

Infectious diseases declined drastically in the 20th century. The CDC reports many diseases that were once common in the United States have been virtually eliminated because of vaccination.