The White House is rushing ahead to roll out a new COVID-19 booster shot campaign in early September, but is facing an uphill battle to ensure it is successful.  

The vaccines being used in the campaign are the first ones that have been manufactured to specifically target the subvariants of omicron that are currently causing the most infections, and administration officials have indicated they’re preparing to start offering the shots shortly after Labor Day.

Immunity from the initial round of vaccines is waning and health officials said they want to ensure the public is protected as much as possible against another wave of infections in the fall and winter. Right now, close to 450 Americans are dying every day from the virus, and there’s concern the numbers could rise as people move indoors.

Both Pfizer and Moderna have asked the Food and Drug Administration (FDA) for emergency use authorization for booster shots that target the omicron BA.4 and BA.5 subvariants. Pfizer’s vaccine will be for everyone aged 12 and older, while Moderna’s will be meant just for adults aged 18 and older.

Administration officials say these new vaccines will be key to controlling a potential fall surge, but they will need to convince an increasingly checked-out public to get the shots.

White House COVID-19 response coordinator Ashish Jha has been front and center trying to promote the reformulated boosters, saying recently that “all the data suggests [they] should be highly effective against the new variants.”

“The big picture bottom line is these are substantial upgrades in our vaccines in terms of their ability to prevent infection, to prevent transmission. Certainly to prevent serious illness. And so it’s going to be really important that people this fall and winter get the new shot.” Jha said during a U.S. Chamber of Commerce event on Aug. 16. 

During an interview with the radio program “Conversations on Health Care,” Centers for Disease Control and Prevention (CDC) Director Rochelle Walensky said the administration wants to provide people with the broadest possible protection.

“So the strategy now is to tailor vaccine for giving us the largest breadth of response, ideally one that would have less waning over time,” Walensky said. “I believe it is best to use a vaccine that is tailored for the variant that we have right now.”

But despite the administration’s optimism, the effort is likely to face major hurdles. Chief among them is a lack of interest from the public. Only about two-thirds of the U.S. population have been vaccinated with a primary COVID-19 vaccine series, while less than half of that group has received even a first booster.  

The vaccination rate among children is even lower. According to the CDC, less than 4 percent of eligible kids under the age of 2 have received at least one dose, and only 6 percent of kids between the ages of 2 and 4 have received a single dose. 

Rupali Limaye, a vaccine expert at the Johns Hopkins Bloomberg School of Public Health, said she doesn’t expect the retooled boosters will do much to convince the under-vaccinated population to get another shot. 

The same people who rushed to get the initial vaccine series and then the first round of boosters will be the ones to receive the omicron-specific shots, she said, and mixed messages from health officials are partly to blame. 

The most recent update to the CDC’s guidance emphasized living with the virus, and downplayed many of its previously recommended mitigation strategies. That doesn’t necessarily mesh with the idea that the public urgently needs to get an updated vaccine.

“I think for the most part, the majority of the public has sort of moved on, if you will. And the messaging has been that this is going to now be with us,” Limaye said. “Why do I need a new vaccine related to a virus that essentially my government has told me is no longer an issue?”

Rather than a broad rollout of the updated vaccines for the general public, Limaye and other scientists have suggested a more targeted approach, tailoring vaccine recommendations to the elderly and immunocompromised. 

John Moore, a virologist at Weill Cornell Medicine, said it’s not clear how much extra protection the new shots would provide against infection, but predicted they won’t be much better than the first round of boosters.

The protection is likely “somewhere between mediocre and reasonable. I mean, we just don’t know,” Moore said. “A booster will give some additional protection against infection for, you know, a few months before it wanes again.”

Moore said it’s important that health officials provide the public with realistic messaging, and don’t oversell the benefits of the shots.

“It’s not like they’re a magic bullet that gives you super strong protection,” Moore said. “If the public thinks they’re getting something that is really, really against infection, then they might change their behavior and increase the risk of exposure. That’s counterproductive.” 

The other concern among some scientists is that the government is moving too quickly to authorize the vaccines. Neither Moderna nor Pfizer has clinical trial data for the vaccine. Instead, their requests are based on data from a booster targeting an earlier version of omicron, as well as preclinical data from mice.

But health officials maintain they don’t need additional data, because vaccine manufacturers are essentially making a minor update to the existing vaccine, which has an established track record of success.

“There’s always a question here of being too slow versus too fast, and I think one of the challenges is if we wait for those data to emerge in human data, not just mice data, in human data, we will be using what I would consider to be a potentially outdated vaccine,” Walensky said. “I believe it is best to use a vaccine that is tailored for the variant that we have right now.”