In a new CDC report, these immunizations aid against emergency department and urgent care encounters in immunocompetent adults.
In the latest CDC MMWR report, investigators determined a bivalent booster dose among immunocompetent adults were able to gain additional protection and helped to prevent people from emergency department and urgent care encounters.
“The VISION1 Network looked at the vaccine effectiveness (VE) of a bivalent mRNA booster dose (after 2, 3, or 4 monovalent doses) compared with no previous vaccination and 2 previous receipt of 2, 3, or 4 monovalent-only mRNA vaccine doses, among immunocompetent adults aged ≥18 years with an emergency department/urgent care (ED/UC) encounter or hospitalization for a COVID-19–like illness,” the authors wrote.
“VE of a bivalent booster dose (after 2, 3, or 4 monovalent doses) against COVID-19–associated ED/UC encounters was 56% compared with no vaccination, 31% compared with monovalent vaccination only with last dose 2–4 months earlier, and 50% compared with monovalent vaccination only with last dose ≥11 months earlier.”
The bivalent mRNA vaccines (Pfizer-BioNTech and Moderna) contain both the ancestral SARS-CoV-2 strain component plus a component of the Omicron BA.4/BA.5 sublineages.
The authors wrote that, “Because of waning of monovalent vaccine-conferred immunity, relative effectiveness of bivalent vaccines was higher with increased time since the previous monovalent dose.”
Protecting the Immunocompromised
Immunocompromised patients encompass a large heterogeneous population that includes people with diabetes, cancer patients, transplant recipients, and others.
In this early study of immunocompetent adults, significant protection from a booster dose of bivalent mRNA COVID-19 vaccine (after receipt of 2, 3, or 4 monovalent doses) compared with no vaccination was found, as well as significant relative benefits of a bivalent booster dose when compared with previous receipt of monovalent doses only.
“Bivalent booster doses (after receipt of 2, 3, or 4 monovalent doses) were effective in preventing medically attended COVID-19 compared with no previous vaccination among immunocompetent adults and provided additional protection when compared with previous monovalent mRNA vaccine doses only,” the authors concluded. “VE was similar against COVID-19–associated ED/UC encounters and hospitalizations, which might reflect changing severity of hospitalized cases over time.”
1. Established in 2019, the VISION Vaccine Effectiveness (VE) Network is a research collaboration between CDC, Westat, and multiple sites with integrated clinical, laboratory, and vaccination records in the United States that evaluate how well seasonal influenza (flu) vaccines protect people against flu and how well different COVID-19 vaccines protect against COVID-19.