The Impact of Influenza on US Working-Age Adults: Exploring the Benefits of the Recombinant Influenza Vaccine.

Abstract

Despite universal influenza vaccine recommendation in the United States, vaccination coverage rates in working-age adults (aged 18-64 years) remain suboptimal. Studies have suggested that recombinant influenza vaccines (RIVs) offer better protection than standard-dose inactivated influenza vaccines (SD-IIVs) in that demographic. We explored the potential added benefit of recommending RIV for the US working-age population. We gathered data on influenza burden, vaccine effectiveness, and vaccination coverage rate from the US Centers for Disease Control and Prevention (2012-2023, excluding 2020-2021). We conducted a retrospective analysis of the past 10 years to illustrate the influenza burden among adults aged 18-64 years. We performed an age-stratified analysis using prevalence of chronic conditions to assess their impact on influenza hospitalizations and deaths, and estimated reductions in hospitalizations had RIVs been used instead of SD-IIVs during the study period, using an age and risk-group decision-tree model. Over the last decade, influenza caused a median of 151 021 hospitalizations (95% confidence interval, 139 750-164 130) per season among US working-age adults. Adults aged 50-64 years had 3-5-fold higher rates of hospitalization and death than those aged 18-49 years. The 14% of 18-49-year-olds with chronic conditions accounted for >28% of hospitalizations and deaths in this group. If RIVs had been used instead of SD-IIVs, an additional 10 000 hospitalizations could have been prevented each season in these populations. Influenza significantly affects US working-age adults, particularly those aged 50-64 years. Increases in longevity and chronic conditions prevalence are expected, making tailored public health vaccine recommendations important to support healthy aging.