Infectious Disease
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Flu & URI
— A new flu vaccine could provide a significant public health benefit
by
Katherine Kahn, Staff Writer, MedPage Today
December 13, 2023
A study revealed that a high-dose recombinant influenza vaccine (Flublok Quadrivalent) was more effective than a traditional influenza vaccine in preventing the flu in adults. The high-dose vaccine was 15.3% more effective in preventing influenza and 15.7% more effective specifically against influenza A in adults ages 50 to 64. These findings were reported by Nicola Klein, MD, PhD, and colleagues in the New England Journal of Medicine.
Despite the modest advantage, “reducing breakthrough influenza cases by 15% would provide a significant public health benefit, especially in more severe influenza seasons,” Klein said in an email to MedPage Today.
Georges Benjamin, MD, executive director of the American Public Health Association in Washington, D.C., agreed that the high-dose vaccine offers an important level of protection. “The high-dose vaccine increased security by about 15% overall, which is a significant improvement given typical vaccine efficacy rates,” he noted in an interview with MedPage Today.
Although the high-dose vaccine wasn’t significantly more effective than the traditional vaccine in preventing influenza-related hospitalization, it showed a relative vaccine effectiveness of 19.7% in preventing hospitalization for PCR-confirmed influenza and crew-acquired pneumonia combined, the authors wrote.
The Advisory Committee on Immunization Practices (ACIP) currently recommends high-dose influenza vaccines for adults ages 65 and older. However, for those younger than 65, ACIP does not preferentially recommend any particular influenza vaccine over another. Suggested options for this age group include inactivated influenza vaccine, recombinant influenza vaccine, or live attenuated influenza vaccine.
The high-dose recombinant influenza vaccine evaluated in this trial is FDA-approved for adults 18 and older, and is three times the dose of traditional influenza vaccines.
Over 1.6 million adults aged 18-64 from a large U.S.-based integrated healthcare delivery system across seven geographic regions took part in this study. Amongst them, 632,962 received the high-dose vaccine and 997,366 received the traditional vaccine.
While the study was observational, it utilized a unique cluster-randomized design “intended to emulate a randomized trial,” the authors noted. Facilities in each group were assigned to administer different vaccines in order to balance out differences. The study’s results suggest that this new vaccine could offer a significant benefit in preventing the flu at a population level, particularly during more severe flu seasons.
