N Engl J Med
Does high-dose recombinant flu vaccine benefit patients younger than age 65?
The high-dose recombinant vaccine was significantly more effective against PCR-confirmed influenza than an egg-based standard-dose vaccine among adults ages of 50 to 64 years over two influenza seasons.
- In this cluster-randomized observational study, facilities at a California health system routinely administered either a high-dose recombinant influenza vaccine (Flublok Quadrivalent) or one of two standard-dose influenza vaccines during the 2018-2019 and 2019-2020 influenza seasons to adults 50 to 64 years of age (primary age group) and 18 to 49 years of age. Each facility alternated weekly between the two vaccine formulations. Primary outcome was influenza (A or B) confirmed by PCR testing. Secondary outcomes included influenza A, influenza B, and influenza-related hospitalization outcomes.
- The study population included 1,630,328 adults between the ages of 18 and 64 years (632,962 in the recombinant-vaccine group, 997,366 in the standard-dose group). During the study period, 1,386 cases of PCR-confirmed influenza were diagnosed in the recombinant-vaccine group vs. 2,435 cases in the standard-dose group. Among 50- to 64-year-old participants, 559 participants (2.00 cases per 1,000) tested positive for influenza in the recombinant-vaccine group vs. 925 participants (2.34 cases per 1,000) in the standard-dose group (relative vaccine effectiveness, 15.3%; 95% confidence interval [CI], 5.9-23.8; P = 0.002). Relative vaccine effectiveness against influenza A in the same age group was 15.7% (95% CI, 6.0-24.5; P = 0.002). The recombinant vaccine didn’t protect against influenza-related hospitalization to a significantly greater degree than the standard-dose vaccines.
Source:
Hsiao, et al. (2023, December 14). N Engl J Med. Recombinant or Standard-Dose Influenza Vaccine in Adults under 65 Years of Age. https://pubmed.ncbi.nlm.nih.gov/38091531/