CDC: Booster Doses Offer Protection Against Severe COVID-19 during Omicron Wave

July 26, 2022

Third and fourth COVID-19 vaccine doses provided significant protection to healthy adults who were eligible to receive them as the Omicron variant spread during early 2022.

In a new Morbidity and Mortality Weekly Report, the agency evaluated the effectiveness of the COVID-19 vaccines through hundreds of thousands of emergency department/urgent care visits, as well as 58,000 hospitalizations from 10 states from mid-December 2021 through mid-June 2022.

“COVID-19 vaccines remain our single most important tool to protect people against serious illness, hospitalization, and death,” the CDC said in a statement.

Among the key takeaways:

• The issue:  COVID-19 variants have become more adept at evading immune protection against infection. Researchers are evaluating the efficacy of booster doses against infection and severe disease.
• Key Finding: For people 50 and older, during the BA.2/BA.2.12.1 wave, vaccine effectiveness against COVID-associated hospitalization was 55 percent more than four months after a booster/third dose and increased to 80 percent more than a week after the fourth dose.
• Study challenges:  Comparing vaccines is challenging since most people have some degree of existing protection against COVID-19 due to vaccination or prior infection.
• By the numbers:  Fewer than 30 percent of U.S. adults age 50 or older have received a second booster dose, according to CDC data.
• The bottom line: “Booster doses should be obtained immediately when persons become eligible,” the report said.

The report also noted that when BA.1 was the predominant variant, vaccine effectiveness was 61 percent for two doses against COVID-19-associated hospitalizations compared to 85–92 percent after a third dose.

HAP encourages everyone to stay up to date on their COVID-19 vaccines to support the safety and health our communities. Learn more about the available options in your area.

The full report is available to review online.