A comprehensive study from Spain has confirmed the high effectiveness of influenza vaccination in reducing morbidity and mortality across all age groups, with some variations in the effectiveness against specific virus strains.
The research, conducted by a team from CEU San Pablo University in Madrid and published in the European Respiratory Review, analyzed data from over 38 countries and 6.5 million patients. This meta-analysis reinforced the protective benefits of influenza vaccination for children, adults, and the elderly. However, the study noted that the vaccine’s efficacy against influenza A (H3N2) is somewhat lower in older populations due to the virus’s mutation patterns and structural features.
Estanislao Nystal Villan, PhD, the principal investigator, highlighted the challenges posed by the H3N2 strain, which exhibits a high degree of mutations and glycosylation, making it harder for antibodies to neutralize the virus. Despite these challenges, vaccination still plays a crucial role in reducing morbidity and mortality from influenza, including H3N2 infections.
The study’s findings emphasized that vaccines against the main influenza strains—H1N1, H3N2, and influenza B—are highly effective in lowering the risks of severe illness, hospitalization, and death. “The effectiveness of vaccines can be assessed not only by whether infection has occurred, but by the severity of the disease, the likelihood of hospitalization or death,” Nystal Villan stated. He also pointed out the critical importance of vaccination for individuals at higher risk of complications, such as those with cardiovascular or neurodegenerative conditions.
This large-scale analysis reinforces the significance of influenza vaccination as the primary method for preventing severe illness and significantly reducing mortality, particularly among vulnerable populations, and stresses the need for continued vaccination efforts across all age groups.
