Relationship between the response to influenza vaccination and the nutritional status in institutionalized elderly subjects

Background. Influenza is a major health problem among elderly people in ind ustrialized countries. Nursing homes may be a particularly good setting for outbreaks of influenza. Thus, the aim of the present study was to evaluate some aspects of the nutritional status of institutionalized elderly subjec ts in relation to their response to influenza vaccination. Certain aspects of the cellular immune response were also investigated. Methods. Twenty-three patients participated in this cross-sectional study. All patients were vaccinated on day 0 with FluviralR, 1994-95 preparation: A/Shangdon/09/93, A/Texas/36/91, B/Panama/45/90. At the same time the preva ccination antibody titer, the nutritional status by the Mini Nutritional As sessment, biochemical parameters, and lymphocyte proliferation were assesse d. On day 28, the postvaccination antibody titer was determined. The determ ination of pre- and postvaccination antibody titers against the various inf luenza antigens was carried out by the hemagglutination inhibition test. An increase of 4x for any of the virus antigens was considered as a seroconve rsion. A titer higher than 40 at the prevaccination period was considered a s protective. Results. Eleven elderly subjects were responsive and 12 were not. We have s hown that the nutritional parameters such as hemoglobin, hematocrit, total protein, iron and vitamin E levels, as well as the DHEA level and the cellu lar immune response were significantly lower in the nonresponsive group as compared to the responsive group. Thus, they might be associated with the i nfluenza vaccine responsiveness of institutionalized elderly subjects. Conclusions. These results will help design intervention studies for improv ing the immune response by achieving an optimal nutritional status, mainly in the frail elderly population, that could have a great public health impa ct.