March 2023

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Health Capsule

Bivalent Boosters Block Severe COVID-19

COVID-19 vaccines have saved many lives. The original vaccines were released in late 2020. They targeted the initial strain of SARS-CoV-2, the virus that causes COVID-19. Since then, different versions of the virus have evolved. So scientists created an updated booster shot. It’s called a bivalent booster because it targets two versions of the virus: the original strain and a newer one called Omicron.

Earlier research showed that the bivalent boosters were safe. A new study found that they’re also better than the original booster at reducing the risk of severe disease.

Scientists looked at vaccine data collected in North Carolina in 2022. Nearly 300,000 people received one of the original boosters. More than 1 million got one of the updated boosters. The researchers compared these two groups. They looked at hospitalizations and deaths from COVID-19 from about two weeks to three months after the shots were given.

The team found that the updated booster was 62% effective at blocking severe COVID-19. The original booster was only about 25% effective. Overall, the updated shots were 37% more effective than the original boosters.

“The increased effectiveness found in this study demonstrates why it’s important for people to protect themselves with the updated booster, even if they had already gotten the original booster dose,” says Dr. Zack Moore of the North Carolina Department of Health and Human Services.