THURSDAY, Jan. 26, 2023 (HealthDay News) -- Bivalent vaccines seem to provide additional protection against symptomatic BA.5 and XBB/XBB.1.5 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) omicron sublineages, according to research published in the Jan. 27 issue of the U.S. Centers for Disease Control and Prevention Morbidity and Mortality Weekly Report.
Ruth Link-Gelles, Ph.D., from the CDC in Atlanta, and colleagues analyzed data from the Increasing Community Access to Testing national pharmacy program for SARS-CoV-2 testing to estimate the vaccine effectiveness of updated (bivalent) mRNA COVID-19 vaccines against symptomatic infection caused by BA.5-related and XBB/XBB.1.5-related sublineages among adults during Dec. 1, 2022, to Jan. 13, 2023. A total of 29,175 nucleic acid amplification tests were included from adults who had previously received two to four monovalent COVID-19 vaccine doses.
The researchers found that for adults aged 18 to 49 years, the relative vaccine effectiveness of a bivalent booster given two to three months earlier was 52 and 48 percent against symptomatic BA.5 infection and against symptomatic XBB/XBB.1.5 infection, respectively, compared with no bivalent booster.
"All persons should stay up to date with recommended COVID-19 vaccines, including receiving a bivalent booster dose when eligible," the authors write.