The Omicron wave in the U.S. has subsided in recent weeks, and case numbers, hospitalizations, and deaths remain in decline in most parts of the country.
The good news has prompted many cities and states to eliminate mask mandates and end vaccine requirements. And on top of that, despite the variant, people who are fully vaccinated seem to be faring well against death and severe disease.
But a recent study from the Centers for Disease Control and Prevention found that the immunities from boosters may begin to wane as early as four months after receiving them.
So the question remains: Will another booster shot be necessary for everyone to stay safe, especially if another variant comes this spring?
Here’s what experts had to say:
Will you need another booster?
There are no clear-cut rules about if and when you should get another booster if you’ve already received one. However, the CDC has already recommended that some vulnerable populations schedule a fourth booster.
A series of studies published in recent months suggest that receiving a third booster shot, in addition to two vaccine shots, may be enough to protect you against serious illness or death from COVID for months, and even longer.
The diversity of antibodies produced by three shots of the mRNA vaccines made by Pfizer-BioNTech and Moderna offer protection against any existing or new coronavirus variants, and may last for years, according to the studies, the most recent of which was published Feb. 15.
Last month, White House chief medical adviser Dr. Anthony Fauci suggested that healthy individuals who are boosted may not need another COVID vaccine for years.
“It will depend on who you are,” Fauci said. “But if you are a normal, healthy 30-year-old person with no underlying conditions, you might need a booster only every four or five years.”
The CDC recommended in February that all adults who are moderately or severely immunocompromised receive a fourth dose of the vaccine at least three months after their third booster.
Both of the experts that Fortune spoke with said that the likelihood you will need a fourth booster will probably depend on the virulence and severity of the next coronavirus variant.
“I think depending on what the new variants bring, there could be additional rounds of vaccination that will be required,” said Dr. William Checkley, a pulmonary and critical care physician at the Johns Hopkins Hospital and associate professor of medicine at Johns Hopkins University.
Dr. Gregg Miller, an emergency room doctor in Washington State and chief medical officer at Vituity, a physician-owned health care company, agrees. If another variant comes along, a fourth booster shot could improve chances at combating severe illness.
“There’s certainly every reason to think that whatever variant that comes out in the future, our prior protection will still be somewhat protective against the future variant,” Miller told Fortune, but added that each future variant will be able to “jump that wall of immunity.”
“The higher and higher you build up that wall, the harder and harder it’s going to be for future variants to jump over it,” he said.
The next variant
While the worst of Omicron is likely behind us, experts warn that the pandemic is unpredictable, and a new variant is likely.
For Checkley, the question of another variant is not a matter of if, but when.
“It’s just a matter of time,” he told Fortune. “Especially given that the virus is still circulating amid populations in places that continue to have low vaccination rates.”
COVID is more likely to mutate into a new variant when it has the opportunity to spread among populations that take fewer preventive measures to stop its spread, like wearing masks or getting vaccinated.
“It’s about encouraging communities, encouraging countries to increase the rates of vaccination, and to get it to levels where they’re high enough to reduce the replication of the virus,” said Checkley. “Which also reduces the chances of the formation of variants.”
One new subvariant is already here. Omicron BA.2, also referred to as “stealth Omicron,” has now been detected in every U.S. state.
Initial data is unclear on whether it causes a more severe reaction than the initial Omicron variant, but a recent study from Japan showed that stealth Omicron could be as much as 30% more transmissible.
How can you protect yourself?
Although there is no official fourth-dose boosting guidance for people with healthy immune systems, experts across the board say the best way anyone can protect themselves against future COVID variants is to be fully vaccinated to begin with.
Wearing a mask and practicing social distancing are still effective methods of reducing the virus’s ability to circulate. The country should prepare for them to continue to be a part of daily life as we move toward treating COVID-19 like the flu or other endemic diseases, Checkley said.
And if you begin feeling symptoms, it’s important to get tested immediately, according to Miller. Effective COVID treatments, like Pfizer’s antiviral pill, reduce the chances of hospitalization by 90%.
“Those pills are most effective the sooner you take them,” Miller said. “So you don’t want to wait a week and realize you’re not getting better before you get tested and realize it’s too late to get treated.”
