Can a short period of micronutrient supplementation in older institutionalized people improve response to influenza vaccine? A randomized, controlled trial

OBJECTIVES: To test the hypothesis that a micronutrient supplement can improve seroconversion after influenza immunization in older institutionalized people. DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Nursing and residential homes in Liverpool, United Kingdom. PARTICIPANTS: One hundred sixty-four residents aged 60 and older from 31 homes were initially randomized; of these, 119 (72.6%) completed the study. INTERVENTION: Participants were randomized to receive a micronutrient supplement providing the reference nutrient intake for all vitamins and trace elements or identical placebo. Tablets were taken over an 8-week period during September and October 2000; influenza vaccine was administered 4 weeks after their commencement. MEASUREMENTS: The hemagglutination-inhibiting antibody response as defined by a fourfold or greater titer rise over 4 weeks and assessed separately for each of the three antigens contained in the 2000/2001 influenza vaccine (A/New Caledonia/20/99 (H1N1), A/Moscow/10/99 (H3N2), B/Beijing/184/93 (B)). RESULTS: Despite a significant increase in serum concentrations of vitamins A, C, D-3, E, folate, and selenium in the supplemented group, there was no significant difference between groups (supplemented vs placebo, respectively) in the proportion of participants seroconverting to H1N1 (41% vs 49%, P=.374), H3N2 (49% vs 58%, P=.343), or B (41% vs 40%, P=.944). CONCLUSION: A micronutrient supplement providing the reference nutrient intake administered over 8 weeks had no beneficial effect on antibody response to influenza vaccine in older people living in long-term care.

Is influenza vaccination cost effective for healthy people between ages 65 and 74 years? A randomised controlled trial

The aim of this study was to determine the cost effectiveness of influenza vaccination for healthy people aged 65-74 years living in the UK. People without risk factors for influenza (chronic heart, lung or renal disease, diabetic, immuno-suppressed or those living in an institution) were identified from 20 general practitioner (GP) practices in Liverpool in September 1999. 729/5875 (12.4%) eligible individuals were recruited and randomised to receive either influenza vaccine or placebo (ratio 3: 1)! with all participants receiving 23-valent-pneumococcal polysaccharide vaccine unless already administered. The primary analysis was the frequency of influenza as recorded by a GP diagnosis of pneumonia or influenza like illness. In 2000, the UK vaccination policy was changed with influenza vaccine becoming available. for all people aged 65 years and over irrespective of risk. As a consequence of this policy change. the study had to be fundamentally restructured and only results obtained over a one rather than the originally planned two-year randomised controlled trial framework were used. Results from 1999/2000 demonstrated no significant difference between groups for the primary outcome (relative risk 0.8, 95%, CI 0.16-4.1). In addition. there were no deaths or hospitalisations for influenza associated respiratory illness in either group. The subsequent analysis. using both national and local sources of evidence, estimated the following cost effectiveness indicators: (1) incremental NHS cost per GP consultation avoided = pound2000; (2) incremental NHS cost per hospital admission avoided = pound61,000: (3) incremental NHS cost per death avoided = pound1.900.000 and (4) incremental NHS cost per QALY gained = pound304,000. The analysis suggested that influenza vaccination in this Population would not be cost effective. (C) 2004 Elsevier Ltd. All rights reserved.