Fauci says variants are ‘wild card’ in COVID-19 booster vaccine equation

Dr. Anthony Fauci, the nation’s top infectious disease expert, said he feels confident in current indications of the enduring efficacy of COVID-19 vaccines, but Fauci said that there’s a worrisome "wild card" factoring into the calculation of whether booster shots will be needed down the road: emerging coronavirus variants.

In an interview with FOX Television Stations Tuesday, Fauci said divergent mutations of the virus present challenges in the race to vaccinate, but until there is conclusive evidence indicating the need for coronavirus boosters, getting a shot into the arms of as many people as possible remains the best course of action. 

Vaccine makers and researchers are racing to determine exactly how long COVID-19 inoculations protect people and whether or not booster shots will play a vital role in preventing another global pandemic in the future. 

Will COVID-19 booster vaccines be necessary? 

Experts have said it’s likely that the novel coronavirus may never go away, but may instead turn into a seasonal annoyance like the flu, requiring regular inoculations to protect people from future outbreaks. But a direct comparison between the seasonal flu vaccine and the COVID-19 vaccine isn’t entirely accurate, Fauci said.

The seasonal flu vaccine is between 40% and 60% effective, although its efficacy varies from year to year. Still, the 2019-2020 flu vaccination prevented an estimated 7.5 million influenza illnesses and another 3.7 million influenza-associated medical visits, according to the CDC.

But Fauci says it’s difficult to compare the two vaccines because the efficacy of the COVID-19 vaccines "is substantially greater than even the best of the influenza."

According to a recent study from Pfizer, the company’s COVID-19 vaccine maintains more than 90% efficacy at six months after receiving the second dose. Moderna released similar findings on the efficacy of its own vaccine on Tuesday. 

RELATED: Moderna COVID-19 vaccine protection lasts at least 6 months, study finds

Researchers said ongoing studies are monitoring the vaccine’s immune response beyond six months. Both Moderna and Pfizer have said they are also working to update their vaccines, or possibly design a booster shot, in case they’re needed against troubling new variants — or versions of the coronavirus —  that are circulating.

The current dearth of data on vaccine efficacy after the six-month mark illustrates how much remains unknown more than a year into the ever-changing pandemic.

The first person in the U.S. to receive a COVID-19 vaccination got their shot in December. That first vaccination gave way to an all-out effort to get shots into the arms of beleaguered front-line health care workers, who faced wave after wave of critically ill coronavirus patients filling the halls of ICUs across the U.S.

For those health care workers who were among the earliest vaccinated, the existing data on the length of vaccine efficacy paints an incomplete picture of how long they can expect to be fully protected against the virus. Fauci said it’s just too soon to tell.

"We don’t know the answer to that for the simple reason that we don't know what the durability of the protection against the standard virus is," Fauci said. "The most recent reports said at least six months but it might be much longer than it could be years for all we know."

Fauci said it is entirely conceivable that vaccinated people may need to get booster vaccines down the road, but he doesn’t yet know what the intervals will be between getting a vaccine and a potential booster shot — if booster shots ever come. 

Hoping for the best, preparing for the worst

It’s "feasible" that there may not be a need for COVID-19 booster shots, according to Fauci, but he said the National Institutes of Health and the U.S. Centers for Disease Control and Prevention are currently planning for the worst.

"You want to be prepared in case you have to," Fauci said. "So we’re making the assumption that we’re going to have to boost people, but we may not have to."

Fauci explained that when people are first vaccinated, the level of antibodies that protect them against the novel coronavirus are extremely high. As time goes by, antibodies slowly diminish, but it remains unclear how much time must elapse before a vaccinated person might eventually reach a critical point where they would need to receive a potential vaccine boost. 

RELATED: UK variant a 'brand new ballgame,' infecting children in US 'very readily,' epidemiologist warns

Fauci said there is still "a ways to go" before most vaccinated people need to start worrying about their vaccine’s efficacy diminishing substantively. "The idea is to prevent replication of the virus in order to avoid giving the virus a chance to mutate further and require an altered vaccine seasonally," he said. 

Due to a lack of data, the NIH and the CDC aren’t currently working on rolling out guidance or messaging around booster vaccines, but if and when they’re needed, the vaccines will be there. 
"We’re going to be stockpiling enough vaccines to be able to give boosters to people," Fauci said. "We’re also doing some clinical trials to see if you boost, what happens to the level of total antibodies, what happens to the level of antibodies against the variant, so we’re anticipating the need to be able to adjust to these variants that might arise, and we’re doing the clinical trials as well as purchasing more vaccine in case we do have to boost people."

As to what a potential COVID-19 vaccine booster could look like, Fauci said additional doses could be drawn from current vaccine stockpiles, but the NIH is currently testing a boost that would specifically target mutations of the virus. 

If vaccine booster shots do become necessary, Fauci said it would be optimal for people to get the same vaccine they received the first time, but there are currently studies underway to see if individuals can mix and match vaccines down the road. 

For now, Fauci said the goal should be getting as many people vaccinated as possible — not just in the U.S., but around the world.

"If we suppress it in the United States or in the developed world, that’s going to be great," Fauci said. "Now, this brings up an important question: As long as you have virus replicating anywhere in the world, the chances of developing variants are considerable, which will ultimately come back and could perhaps negatively impact our own response. That’s one of the real prevailing arguments for why we need to make sure the whole world gets vaccinated – not just the people in the developed world."

Fauci says B.1.1.7 no match for vaccines, but other variants could be

But even though Fauci believes we haven't lost the race to vaccinate, he is still concerned about the ongoing mutations circulating around the world, specifically the B.1.1.7 variant that originated in the U.K. 

Speaking in an interview Sunday on on "Meet the Press." Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy, called the B.1.1.7 variant of the coronavirus "A brand new ballgame."

"In fact, right here in Minnesota, we're now seeing the other aspect of this B.1.1.7 variant that hasn't been talked much about, and that is the fact that it infects kids very readily," Osterholm said.

RELATED: New 'double mutant' coronavirus variant detected in India

Fauci agreed with Osterholm’s concerns about the rapidity with which the U.K. variant seems to spread, but expressed confidence in the vaccines’ effectiveness against it. 

But the effectiveness of existing vaccines against emerging variants is not guaranteed.

A new, concerning "double mutant" variant out of India has recently been detected in parts of California, KTVU FOX 2 reported on Sunday.

"If you are in an elevator with someone that is infected with the variant you are more likely to be infected by that variant," said Dr. Ben Pinsky, Stanford Clinical Virology Lab director. 

Fauci said he takes "every variant seriously," but it is yet to be determined if the India variant eludes current vaccines. 

"I’d like to make sure we match it up against the antibodies the vaccine induces. If the variant eludes the vaccine then I get more worried about it," Fauci said. 

"You know, variants are a risk to anyone who is not fully protected against it," Fauci said. "So, for example, there are some variants – like B.1.1.7 – that vaccines cover them very well. There are other variants, like B.1.351 from South Africa, where protection against any symptomatic disease diminishes by a fair amount, but protection against severe disease, hospitalization and deaths is very good."

"So what might happen is that when you get these new variants, some of them may not be protected against when you’re talking about mild-to-moderate disease, but at the same time, people are not going to get severely ill and wind up dying," Fauci explained. 

To date, there have been more than 15,500 total cases of B.1.1.7 reported since it was first detected in the U.S. in December, data from the CDC shows.

Large events still pose substantial risks, Fauci says

Despite his confidence in the current supply and effectiveness of coronavirus vaccines, Fauci expressed concerns over the return of some public events, urging Americans not to declare premature victory over the pandemic. 

On Monday, the Texas Rangers held the first full-capacity professional sports event of the COVID-19 pandemic. It was the first home game for the team with fans at the new Globe Life Field and it was also the first time attendance restrictions were not in effect for any major sporting event in the United States.

The game was declared a sellout, with 38,238 people in the stands, the Rangers announced.

While Fauci, an avid baseball fan, has previously said that returning to a baseball game is at the "top" of his to-do list once conditions warrant, he probably won’t be attending a game until most fans are vaccinated.

In response to a question on whether he would go to a packed Nationals game if he knew everyone had been vaccinated, Fauci said, "You gave a beautiful hypothetical. I would hope that we would have that situation where everyone agrees to get vaccinated, which I really hope they do, because the more people get vaccinated, the greater proportion of people that get vaccinated, the more easy it will be to get to the point where you could sit at an unlimited capacity Nat game, have a hotdog and a beer and not worry about anything."

Fauci said if everyone was vaccinated, he would feel confident enough in the efficacy of the vaccine that he would attend a packed game. "It doesn’t have to be everybody. If it was 95 percent of the people, I’d still feel comfortable," Fauci said.