What is already known about this topic?
In the United States, COVID-19 monovalent booster vaccination was previously recommended, but related protection decreased after the emergence of Omicron subvariants.
What is added by this report?
In fall 2022, CDC recommended a bivalent mRNA COVID-19 vaccine booster dose for persons aged ≥5 years, administered ≥2 months after completing the primary series or after receipt of a monovalent booster dose.
What are the implications for public health practice?
Bivalent COVID-19 vaccine booster doses might improve protection against SARS-CoV-2 Omicron sublineages and, along with completion of a primary series in persons who remain unvaccinated, are important to protect against COVID-19, particularly among those persons who are at increased risk for severe illness and death.