How Long Will Immunity Last With the New COVID Bivalent Booster?

As we face a surge in COVID cases this fall and winter, you might be trying to decide when to get the new COVID-19 bivalent booster. If you’re wondering how long immunity from the booster will last, you’re not alone.

The new boosters were only just authorized by the Food and Drug Administration (FDA) at the end of August, so we don’t yet have the information we need to know for sure how long immunity from the shots will last.

However, existing data from other experimental vaccines targeting COVID-19 variants suggests protection will last for at least a month. And the experts we spoke with projected about four to six months of COVID-19 protection.

Even if we’re still learning about the duration of immunity, we know that COVID vaccines and boosters help prevent serious outcomes, including severe illness, hospitalizations, and death.

Here’s what experts want you to understand about how long you can expect to be protected by the bivalent booster.

If I Get Boosted Now, How Long Will I Be Protected?

To understand the potential immunity conferred by the updated shot, it’s important to know what it was designed to protect against. It targets the original strain of COVID by boosting previous immunity generated by vaccination. It also provides specific immunity to current and highly transmissible circulating SARS-CoV-2 variants, including Omicron BA.5 and others.

Because people are only just beginning to get vaccinated with this Omicron-targeted vaccine, there’s not a lot of documentation about how many COVID cases, hospitalizations, or even deaths occurred in those who received it.

“We don’t have this data yet, but we should be seeing something soon from a study done earlier this year with a BA.1 bivalent vaccine,” Andy Pekosz, PhD, a professor of molecular microbiology and immunology at the Johns Hopkins Bloomberg School of Public Health, told Verywell.

According to that study—which was published in the New England Journal of Medicine—the bivalent vaccine provided protection for at least a month. It also triggered a higher binding antibody response against other COVID variants, including alpha, beta, gamma, and delta.

However, considering that study was only over a month, other experts believe that immunity from the updated shots will likely last much longer.

Previous data that included other bivalent COVID vaccines found they could provide immunity and protection for up to six months.

“We know that immunity was restored anywhere from four to six months with the original boosters,” Mahdee Sobhanie, MD, infectious disease physician at The Ohio State University Wexner Medical Center, told Verywell. “So it’s possible that these boosters are going to last that long because they have the same mechanism—or they work the same way—as the original boosters do, but time is going to tell.”

Natasha Bhuyan, MD, a family physician in Phoenix, Arizona, told Verywell that based on what we know about prior vaccines, there’s no reason to believe that immunity from the boosters would not last at least four to six months.

According to Bhuyan, another reason for extended protection is that we “haven’t seen a huge emergence of new variants, likely because COVID cases are not surging [and] variants are more likely to occur during a surge.”

Sobhanie and Bhuyan agreed that with more time, we’ll get a better idea about how long we can expect the bivalent boosters to offer protection.

Which Factors Affect Booster Immunity? 

Pekosz said that how long immunity lasts after getting a bivalent booster will really depend on each person. For example, previous vaccinations and natural immunity from prior infections play a role, in addition to high or low vaccination rates in a community.

“All of these factors can contribute to how well and how long a person’s immune response will last,” said Pekosz. “It makes making broad predictions a bit difficult because the population has a lot of COVID-19 immunity that has been acquired through many different combinations of vaccination, boosters, and infection.” 

Your Immune System

Sobhanie added that immunity also depends on how well a person’s immune system is working.

For example, people with certain health conditions or taking certain medications, organ transplant recipients, and cancer patients undergoing chemotherapy may have weaker immune systems.

“Those patients may not have as long as immunity as somebody who has an intact immune system,” Sobhanie said.

However, if those circumstances apply, Sobhanie emphasized that “we still recommend that you get vaccinated because you do build some immunity as a result.”

New Variants

Beyond individual factors, Bhuyan added that if another COVID variant or mutation pops up, that could also affect immunity.

“With prior COVID vaccines, we did see immunity decrease even just 12 weeks after the vaccine,” said Bhuyan. “However, this doesn’t mean the vaccines are completely ineffective after 12 weeks—it just means they are not more than 95% protective at that point.”

Is It Worth Getting the Booster?

Even though researchers are still learning about how long immunity is expected to last and how much protection you’ll get from the bivalent booster, that doesn’t mean people should avoid getting it.

“Everyone who is eligible should receive the booster, as it should work better than previous boosters,” said Pekosz. “Boosting is one part of the strategy to deal with COVID-19 going forward. Vaccination, testing, and antivirals should be used together to limit severe COVID-19, especially in the highly vulnerable populations.”

The Centers for Disease Control and Prevention (CDC) recommends that people aged 12 and older get one updated bivalent booster shot if they are at least two months out from their last COVID vaccine dose—whether that’s from their primary series dose or their most recent booster shot.

If you currently have COVID or recently had it, consider putting off getting your bivalent booster shot for about three months from when you had a positive COVID test or when your symptoms started.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.