High-dose (HD) and adjuvanted influenza vaccines provided the best protection for people ages 65 and older against symptoms and hospitalization during the 2022-23 influenza season, a real-world study concluded. study published this week in Clinical infectious diseases.
High-dose flu vaccines contain four times the standard dose (SD), while adjuvanted vaccines contain an additional immune-boosting agent. In 2022, the U.S. Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices recommended high-dose, adjuvanted, or recombinant (cell-based) vaccines instead of SD vaccines for older adults who are at increased risk for severe illness and flu-related hospitalization and death.
Researchers at Kaiser Permanente Southern California conducted a retrospective study to evaluate the comparative vaccine efficacy (cVE) of cell-based HD, adjuvanted, and SD influenza vaccines compared to egg-based SD vaccines.
Participants were 495,119 adults with a mean age of 73 years who received one dose of influenza vaccine from August to December 2022 and were followed until May 2023. Of all participants, 54.9% were women and 46.3% were white.
“Overall, the effectiveness of the influenza vaccination (VE) has remained low (
Adjuvanted vaccines most effective
Overall, 74.8% of participants received high-dose influenza vaccines and the remainder received SD egg-based (13.9%), SD cell-based (6.5%), or adjuvanted (4.7%) vaccines.
