Representatives from Austin Public Health said they are prepared to offer COVID-19 vaccine booster shots to the Austin-Travis County community this year if the U.S. Food & Drug Administration recommends it.

At a June 4 news conference, Cassandra Deleon, APH chief administrative officer for disease prevention and health promotion, said she expected that booster shots would be recommended to maintain the level of immunity provided by the two-dose Pfizer and Moderna vaccines and the one-shot Johnson & Johnson vaccine.

"We are anticipating that a booster vaccine will be something that we may have to roll out in the fall," Deleon said. "We feel confident and ready, and we have the resources ready to deploy so we can meet that community need, should it come up."

Vaccine manufacturers are conducting ongoing clinical trials to measure the ongoing effectiveness of the vaccines and whether their protection diminishes over time. In April, Pfizer CEO Albert Bourla told reporters at an event with CVS Health it was "a likely scenario" that a third Pfizer dose would be needed between six and 12 months after the second dose. Bourla also said the emergence of coronavirus variants "will play a key role" in the need for a booster. Additionally, Alex Gorskey, CEO of Johnson & Johnson, told CNBC that annual COVID-19 shots could be needed.

"Vaccine [manufacturers are] looking at if a booster becomes something that we need, that the next booster incorporates variants that are circulating around the world. And so we anticipate that a booster may incorporate maybe a different vaccine, and not the vaccine we have," Deleon said.

APH is still pushing to increase vaccine uptake for initial shots, and in recent weeks has shifted focus to a direct outreach model of distribution. Travis County shut down its mass-vaccination site at the Circuit of The Americas—a partnership with other Central Texas counties—in early May, but Deleon said mass sites could be resurrected for booster shot distribution in the fall.

"We anticipate boosters will hit at the same time that flu hits. We always do mass flu clinics in the fall, so we anticipate we would do very similar activities, just potentially on a larger scale," she said.