Influenza and Aging: Clinical Manifestations, Complications, and Treatment Approaches in Older Adults

Influenza, a highly contagious respiratory viral illness, poses significant global health risks, particularly affecting older and those with chronic health conditions. Influenza viruses, primarily types A and B, are responsible for seasonal human infections and exhibit a propensity for antigenic drift and shift, contributing to seasonal epidemics and pandemics. The severity of influenza varies, but severe cases often lead to pneumonia, acute respiratory distress syndrome, and multiorgan failure. Older adults, especially those over 65 years of age, face increased risks of immune senescence, chronic comorbidities, and decreased vaccine efficacy. Globally, influenza affects millions of people annually, with significant morbidity and mortality among older. Epidemiological patterns vary with climate, and risk factors include age, immunocompromised status, and preexisting chronic conditions. In older adults, influenza frequently results in hospitalization and death, which is exacerbated by immunosenescence and biological organ changes associated with aging. Clinical manifestations range from mild symptoms to severe complications such as viral pneumonia and multiorgan failure. Diagnosis often relies on antigen or molecular tests, with radiological examination aiding in severe cases. Treatment primarily involves antiviral agents, such as oseltamivir and peramivir, with the greatest benefit observed when initiated early. Management of severe cases may require hospitalization and supportive care, including addressing complications, such as secondary bacterial infections and cardiovascular events. This article highlights the need for improved vaccination strategies and novel treatments, including monoclonal antibodies and adoptive T cell therapies, to better manage severe influenza infections in vulnerable populations such as older.