With COVID on the rise, should you wait for the new booster or get the old one? What experts say

Clearly, the situation isn’t ideal—certainly not ahead of the Labor Day weekend.

COVID-related hospitalizations rose nearly 22% from Aug. 6-12, the latest period for which data is available, according to the U.S. Centers for Disease Control and Prevention. Deaths rose similarly—by 21% Aug. 13-19, when compared to the week prior.

Updated COVID jabs—tailored to the XBB.1.5 “Kraken” strain that dominated late last year and early this year—are tentatively slated for a September U.S. debut—though likely not until midway through, or late in, the month. 

If you’re behind on COVID vaccinations or due for a booster, should you get one now—or hold out for the latest and (maybe) greatest?

“Most people can probably wait until the new vaccine is available next month,” Dr. Georges Benjamin, executive director of the American Public Health Association, tells Fortune. 

Those who are unvaccinated or behind on their recommended vaccinations, however, “should probably complete their vaccine series now.” And people who are at high risk—due to being immunocompromised, elderly, or other factors—should consult with their doctor to devise a plan ideal for them, he adds.

People with upcoming travel plans—or who plan to attend events—should also consider getting boosted now instead of waiting, Dr. Stuart Ray, vice chair of medicine for data integrity and analytics at Johns Hopkins’ Department of Medicine, tells Fortune.

Others, like Dr. Amesh Adalja—an infectious disease specialist and senior scholar at the Johns Hopkins Center for Health Security—tell Fortune that boosters “should really be targeted to high-risk persons and not universally recommended.”

“Their benefit is really restricted to prevention of severe disease in those who have a risk factor for severe disease,” he says. “Currently, I think high-risk individuals should wait until the updated booster vaccines are available next month.”

A refresher on CDC COVID vaccine recommendations

When it comes to COVID vaccinations and boosters, if you can’t remember who is supposed to get what and when, relax—you’re normal. (We had to look it up too.)

Here’s a refresher, per the CDC:

• Those ages 5 months through 5 years may need multiple doses of the COVID vaccine to get up to date—including one or more boosters tailored to the BA.5 variant. (These were released in the U.S. around Labor Day of last year.) Just how many shots a young child needs will depend on when they were born and how many doses they’ve already received, if any. Talk to your child’s pediatrician for more information.
• Those ages 6 through 64 need their initial set of COVID jabs (usually two), plus one updated BA.5 booster.
• Those ages 65 and older have the same needs, but may require one additional dose of BA.5 booster, for a potential total of two boosters doses.
• Those who are moderately or severely immunocompromised should discuss their specific situation with their doctor.

This CDC hasn’t yet announced what groups, if any, will receive priority for the boosters, or what populations they’ll be recommended for.

Too little, too late?

While updated COVID boosters are mere weeks away from wide availability, they’re tailored to a variant that is now nearly extinct. XBB.1.5 was estimated to comprise less than 5% of U.S. cases as of mid-August, according to the CDC.

Antibody immunity—from vaccination or infection—only lasts three to six months on average, meaning many Americans are in need of renewed protection. The boosters should work against currently leading variants that didn’t exist when they were formulated, like “Eris” EG.5.1 and “Fornax” FL.1.5.1, experts say—to some extent, at least. They’re expected to provide protection against severe disease and death. But whether or not they’re any more effective than currently available boosters remains to be seen.

Scientists, however, are eyeing variants with new key mutations—referred to as “flip” mutations—that could make the virus more problematic, according to Raj Rajnarayanan, assistant dean of research and associate professor at the New York Institute of Technology campus in Jonesboro, Ark., and a top COVID-variant tracker.

Updated boosters may not protect against such variants, Rajnarayanan tells Fortune, adding, “You can see [why] I am not calling this an updated booster anymore.”

This September, the situation will be similar to last September, he says. By the time BA.5 boosters were finally rolled out around Labor Day, the variant wasn’t even among the top five most common anymore.

“Thank God we have Paxlovid,” Rajnarayanan adds, referencing the COVID antiviral.

His vote: Wait for the new booster—it will be worth it, he says. But “it should have been rolled out six months ago.”

It stands to see whether new boosters will be too little, when they’re finally debuted. But some experts are already saying they’ll be too late.

Dr. Eric Topol, a professor of molecular medicine at Scripps Research and founder and director of the Scripps Research Translational Institute, is concerned about the impact of September booster distribution on those who are immunocompromised and elderly.

If new boosters were “coming out imminently next week, or by the end of the month, that would be okay,” he told Fortune earlier this month. “But if you wait until September, October, schools are starting. By then we’re already seeing wastewater levels rise. We have a wave that’s brewing now.”