ST. LOUIS — Viewer Steve Schweizer asked the 5 On Your Side vaccine team, “I just got my second Pfizer vaccination last Thursday, and now am wondering if I should be registering again for a booster in six months?”
Six months, he asks, because that's how long researchers have so far been able to determine the Pfizer and Moderna COVID-19 vaccines are effective against severe cases.
Washington University vaccine researcher Dr. Rachel Presti says we have a lot to learn beyond that, including if or when additional shots are needed.
“We are seeing some post-vaccine infections, although they're rare and they're pretty mild for the most part, so we still think the vaccine is working,” she said. “But what we don't know is, do we need a little bit more immunity to really protect all the people who are at highest risk? And we might need a booster for that.
"Or will the virus change enough that the vaccines don't work as well? And we might need a booster for that. But do we need to get a booster every year like we get a flu vaccine every year? I don't know.”
Recently, Moderna leaders announced the company would have booster doses available by this fall, and Pfizer's CEO announced that people are likely to need a third dose within 12 months of their second. For both companies, the COVID-19 variants are a top priority.
“The thought is that the virus is changing as it's replicating in people, and we may need to not just boost the immune system, but sort of broaden the immune response so that we keep people protected,” said Dr. Presti.
Public health experts emphasize, however, that the guidance on additional vaccines will not come as a directive from vaccine developers, who some are concerned have an interest in promoting the additional use of their products.
"It is going to be a public health decision, it's not going to be a decision that's made by the pharmaceutical company,” said Dr. Anthony Fauci on a recent appearance on Meet the Press. “We're partners with them because they're supplying it; it'll be an FDA-CDC decision.”
Ongoing research will also help determine if we need to get boosters of the same vaccine as the first time around, but Dr. Presti says that's unlikely to be the case.
“I cannot imagine that we would be in a situation where you would need a booster or multiple boosters and we would tell people, no, no, no, you started with Pfizer. You have to stay with Pfizer.”
So at this point, viewers don’t need to book a booster appointment, but it will be important to stay informed as doctors learn more.