What you need to know
- Staying up to date on COVID-19 vaccines helps us remain protected as previous immunity wanes and the virus evolves.
- Bivalent boosters are most important for high-risk individuals, as they are especially vulnerable to severe disease.
- A recent CDC study found that a bivalent booster provided extra protection against infection with XBB.1.5—currently the dominant strain—for at least three months.
Five months after bivalent boosters became available, less than 19 percent of adults have gotten their updated shot. Some experts have been debating who should receive a bivalent booster and how much better it is than the original COVID-19 vaccines. But the experts agree that the authorized bivalent boosters are safe, increase protection, and are especially important for individuals at the highest risk of severe disease.
Why do bivalent boosters matter for COVID-19 immunity?
We can develop immunity against COVID-19 after recovering from an infection or getting a vaccine. But in either case, the protection wanes over time. We also become more vulnerable to infection as the COVID-19 virus evolves into more transmissible strains.
Boosters are important because they can bump up our defenses against the virus, allowing us to stay protected for a longer period of time. Bivalent boosters—which target more than one COVID-19 virus strain—were developed last year to provide better protection against the dominant strains at the time: Omicron subvariants BA.4 and BA.5.
Omicron subvariant XBB.1.5 is now the dominant strain, but recent data shows that the updated boosters continue to be effective. A CDC study published in January found that a bivalent booster provided extra protection against XBB.1.5 infection for at least the first three months after receiving it. Other studies and real-world data have shown that bivalent boosters significantly reduce the risk of hospitalization, especially for older adults. As previous immunity wanes and the COVID-19 virus evolves, staying up to date on COVID-19 vaccines helps us remain protected.
Who should get a bivalent booster?
The CDC recommends bivalent boosters for everyone ages 5 and older, as well as for some kids as young as 6 months old. But the updated shot is most important for high-risk individuals, as they are especially vulnerable to severe disease, hospitalization, and death from COVID-19. People at high risk include those who are ages 65 and older, pregnant, or immunocompromised, as well as those who have underlying medical conditions. Although no vaccine is 100 percent effective, bivalent boosters are one of the best tools we currently have. Using high-quality masks and ventilation tools can also help increase protection.
Is the bivalent booster safe?
Yes. Both Pfizer’s and Moderna’s bivalent boosters are safe. Neither company has reported new safety concerns compared to their original COVID-19 vaccines, and both of these updated shots have been authorized by the FDA and CDC. These two agencies continue to use vaccine monitoring systems to track potential safety signals. Recently, the FDA and CDC investigated a safety signal around Pfizer’s bivalent booster and a potential link to increased risk of stroke in older adults. After conducting a comprehensive data review, the agencies determined that such a link is “very unlikely.”