VACCINE AND NON-PHARMACOLOGICAL MEASURES IN SEASONAL INFLUENZA PREVENTION: CURRENT EVIDENCE ON EFFECTIVENESS

Abstract

Seasonal influenza remains a major cause of acute respiratory morbidity, excess hospitalization, and preventable mortality worldwide, especially among older adults, young children, pregnant women, people with chronic diseases, and healthcare workers. This article reviews current evidence on the effectiveness of vaccination and non-pharmacological measures in seasonal influenza prevention. The manuscript was prepared as a structured narrative review in IMRAD format using contemporary recommendations of the World Health Organization and the U.S. Centers for Disease Control and Prevention, together with systematic reviews, randomized trials, and recent vaccine effectiveness reports. The evidence shows that annual vaccination remains the most effective single preventive intervention and reduces medically attended influenza, hospitalization, and disease severity, although protection varies by age, circulating subtype, and antigenic match. Modern preventive strategy has moved toward more individualized vaccine selection for specific populations, including the use of enhanced formulations for older adults where available. Non-pharmacological measures, including hand hygiene, respiratory etiquette, staying home when ill, improvement of indoor air, surface hygiene, and the selective use of well-fitted masks, provide complementary benefit, particularly during periods of high transmission, in crowded settings, and in households or institutions with vulnerable persons. At the same time, evidence from randomized trials indicates that the effect of masks and hand hygiene alone may be modest when interventions are implemented late or adherence is poor. The most rational modern approach is therefore not to oppose vaccination to non-pharmacological measures, but to combine them in a layered prevention model. Such a model is especially important for high-risk groups, outbreak control, and seasons in which vaccine effectiveness is suboptimal.