How Long Does COVID Immunity Last With The New Bivalent Booster?

In anticipation of a fall and winter surge in COVID cases, new bivalent booster shots are available to anyone older than 12 (or 18 and up if you opt for Moderna instead of Pfizer).

The latest jab protects against the highly transmissible omicron variant while also bumping up protection against the original strain of COVID-19.

If you are at least two months out from your last COVID vaccine or a COVID infection, you can get the booster now. If you were just recently vaccinated or infected, your timeline is a little different.

Either way, it’s important to get this new COVID shot, which can prevent you from severe outcomes, including hospitalization or death, throughout the fall and winter seasons. Just how long will this new shot protect you overall, though? Experts weigh in.

It’s not yet known how long immunity lasts after the new shot, but experts have some theories.

For now, there’s no exact timeline for how long immunity persists after getting the booster, according to Dr. Andy Pekosz, co-director of the Center of Excellence for Influenza Research and Response at the Johns Hopkins Bloomberg School of Public Health. This is because the vaccine is new — it was authorized at the end of August by the Food and Drug Administration.

“It’s important to note that there are lots of studies that are measuring” the immunity timeline, he said ― and many of those studies are happening now.

One study published in the New England Journal of Medicine found that this new shot’s protection lasted at least a month (but it likely lasts longer than that, since the study has measured only a month so far). Additionally, previous studies of other bivalent COVID vaccines showed that immunity lasted about six months.

In time, experts will know how long immunity lasts, but for now, that information is still coming.

Experts have no reason to believe immunity wanes any faster than with previous boosters, so it could last four to six months.

Just how long you’re protected after a COVID booster shot varies from person to person, and it has also rapidly changed as new COVID mutations emerge that can evade antibodies. But generally after previous COVID shots, you were protected for about four to six months.

Both Pekosz and Dr. Benjamin Abramoff, On/Go medical adviser and founder and director of Penn Medicine’s Post-COVID Assessment and Recovery Clinic, said there is no reason to believe your immunity will wane any sooner after this new booster.

“Everything we know about boosters for COVID, as well as for other vaccines, is that you’ll strengthen the long-term immunity ― the memory immunity ― with a booster,” Pekosz said.

In other words, you’re adding on to the immunity you already have from the original vaccine series, the booster, and, for many people, from prior COVID infections, too.

The next time your body sees the virus, you’ll develop a faster and stronger immune response, Pekosz said. “That’s a principle that has shown to be true with other [boosters], and we assume therefore it will be true for this as well.”

This memory immunity also contributes to how quickly you’re protected after vaccination, too. Pekosz said that 10 to 14 days after you get this booster, your antibodies should fully kick in.

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Experts are still learning exactly how long you’re protected from COVID after this new booster shot.

Experts are confident that this booster provides strong protection against the dominant strains of COVID.

“The whole purpose of the new COVID booster is to provide more robust immunity to the current strains of COVID that are in the United States,” Abramoff said. Those strains are the highly contagious BA.4 and BA.5 omicron subvariants but could also be past and future strains of the same omicron lineage.

When looking ahead to winter and the holiday season, this booster shot is intended to produce a strong immune response that, hopefully, prevents a spike in infections and protects folks from severe illness during that time, Abramoff noted.

Remember that the booster is part of a multi-pronged approach to reducing infections.

Even though this booster provides better protection against omicron, you still need to follow public health advice to stay healthy.

“Be cognizant of your symptoms, test if you feel like you may be sick [so] you’re not spreading the virus further,” Abramoff said. “It’s not enough to take the booster without other precautions.”

“Vaccines are [part] of a triple approach: It’s vaccines, testing and antivirals that together really give us the best safety blanket [for] reducing severe disease,” Pekosz added.

If you end up getting sick, it’s not enough to rely on your vaccine for protection. You need to stay home, isolate and talk to your doctor if you fall into a high-risk category. That way you’re protecting yourself and your loved ones from developing severe disease.

Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but guidance can change as scientists discover more about the virus. Please check the Centers for Disease Control and Prevention for the most updated recommendations.