High-dose influenza vaccine: enhanced protection for the elderly

Seasonal influenza causes up to 50 million symptomatic cases and 15,000 - 70,000 deaths annually within the European Union. While influenza affects all age groups, adults aged ≥65 years disproportionately experience high rates of influenza-related hospitalizations and complications. Vaccination remains the cornerstone of influenza prevention and the most effective intervention for reducing morbidity and mortality.

This review focuses on the high-dose inactivated influenza vaccine, an enhanced formulation recommended for the immunization of adults aged 60/65 and older. The high dose vaccine contains four times the hemagglutinin antigen compared to the standard dose vaccine, resulting in significantly higher and more sustained antibody responses. This increased immunogenicity is especially pronounced in adults aged ≥75 years and in those with cardiopulmonary diseases or immunocompromised states.

Expanding the use of the high-dose vaccine to adults aged 50-64 years may proactively address immunosenescence and enhance protection in this population. Moreover, the development of multicomponent vaccines targeting both influenza and COVID-19 within a single formulation could enhance vaccine uptake and streamline immunization programs. Ultimately, the high-dose vaccine has the potential to replace the standard-dose formulation in older adults, thereby optimizing influenza prevention and reducing disease burden.