JACKSONVILLE, Fla. — Moderna now says its COVID-19 vaccine is 93 percent effective through six months after the second shot. Pfizer said last week its vaccine is 91 percent effective through six months after the second shot as well.
Both are calling for booster shots, Moderna says it may be needed before winter. Both are conducting trials looking into a third dose. One of those trials is happening in Jacksonville.
Dr. Michael Koren heads up the Pfizer booster shot study at the Jacksonville Center for Clinical Research. He said there should be a scientific answer about booster shots in two to three months.
"Now, by getting a third vaccine, we may be able to increase antibody levels," he said. "But how that translates into the trade-off of further protection, versus just the side effects of having your immune system reactivated, is something that we're looking at now," Koren said.
"I thought I had a placebo because I had no side effects," Lori Brown, a study participant, said.
Brown enrolled in the Pfizer two-dose COVID vaccine trial last year. She's now a part of the booster study, and got her booster Wednesday.
"I really felt led to do this," she said.
“If t helps others and helps them know what's good and what's wrong, I'm all for it," Brown said.
Brown said her family and friends thought she was crazy to sign up for the initial study at first.
"They were hesitant because, you know, I'm their mother," she said.
Since she has enrolled, however, and her family saw she didn't have side effects from the vaccine, it convinced them to get the shot.
"They figured if a 71-year-old didn't have side effects, they'd be fine, and none of them did [have side effects]," Brown said.
Brown is one of about 150 people participating in the booster study. Koren said they're also evaluating how long initial immunity lasts from the first two doses. They'll also evaluate how the variants impact the vaccine.
“The good news is that the people who are fully vaccinated with the two doses tend to do well. They can still have breakthrough infections, but those infections tend to be mild, and so the vaccines are highly protective," Koren said.
Until they have answers about the booster in two to three months, Koren asks for patience.
“I would encourage people to not go to the extreme of saying, 'I have to get that third dose booster,' because we just don't know if it's really worth it," he said.
As for now, Koren and Brown urge everyone to get the vaccine.
"It's the right thing to do, not only for you and your family, but you know, for the United States," Brown said. “I’d say do it because you're not only affecting yourself and your family, but I mean, one of the quickest ways to fight this is for everybody to be vaccinated," she said.
Koren said both Pfizer and Moderna are looking at reformulating their boosters to be more in tune to fight the delta variant.