The flu vaccine reduces mortality from respiratory disease in the elderly

Vaccination against influenza reduced the number of hospitalizations and deaths due to respiratory diseases in people over 64 years, according to a U.S. study that confirmed the data established in several studies.
The role of influenza vaccination in preventing mortality is poorly quantified, particularly because of the many deaths due to secondary pneumonia or acute exacerbations of chronic diseases, say the authors of the study in the "Journal of Infectious Diseases ".

Only observational studies on the protective effect of influenza vaccine against the most severe diseases exist. One of them suggests that vaccination reduced by 48% the risk of all-cause mortality. Another, conducted in the UK on a smaller cohort, shows that the effectiveness of influenza vaccine was 74.7%, say the authors.

The problem with such studies, they continue, is that vaccinated patients tend to be healthier than others throughout their lives. In addition, according to a test performed in the elderly, influenza vaccination protects against viral flu that 58% of those vaccinated. In fact, it is difficult to conceive that such a vaccine has an effect on mortality, the authors say.

They have therefore compared the admission rates for respiratory diseases and mortality associated with such diseases in those vaccinated more than 64 years in non-vaccinated.

The influenza vaccine reduced by 21% the number of hospitalizations for acute respiratory infection. The rate of reduction attributable to vaccination was 4.15 hospitalizations per 100,000 person-weeks. Among vaccinated individuals, the authors did not observe a significant reduction in the number of hospital admissions outside the influenza season.

The vaccine also reduced mortality from respiratory disease by 12% on average, with a greater efficacy in people with other diseases.

The authors did however not reveal any effect of the vaccine against the risk of all-cause mortality.

They conclude that the effectiveness of influenza vaccine in reducing the number of hospitalizations and mortality due to respiratory diseases in people over 64 years, thus encouraging its use in this population.