Influenza vaccination and all-cause mortality in community-dwelling elderly in Ontario, Canada, a cohort study

The Institute for Clinical Evaluative Sciences, Toronto, Canada.
Vaccine (Impact Factor: 3.62). 10/2010; 29(2):240-6. DOI: 10.1016/j.vaccine.2010.10.049
Source: PubMed


The objective of this study was to evaluate the effectiveness of influenza vaccines in reducing all-cause mortality among community-dwelling elderly. We included 25,922 Ontario residents over age 65 who responded to population health surveys. After full adjustment, influenza vaccination was associated with a statistically significant reduction in all-cause mortality during influenza seasons (hazard ratio (HR)=0.61; 95% CI 0.47-0.79). Contrary to expectations, statistically significant associations between influenza vaccination and mortality were also observed during periods preceding (HR=0.55; 95% CI 0.40-0.75) and following (HR=0.74; 95% CI 0.59-0.94) influenza seasons, indicating the presence of residual confounding. Adjustment for functional status indicators, excluding individuals with high one-year predicted mortality at baseline, and moving the start date of follow-up failed to eliminate the refractory confounding. Since observational studies are prone to bias, future efforts to estimate vaccine effectiveness in the elderly should strive to minimize bias through improved data quality, novel data sources, and/or new analytical techniques.

7 Reads
  • Source
    • "Although the number of individuals tested for cytokine response in our study is too low to draw any firm conclusions, our data suggest a fine line between the benefits of having a strong pro-inflammatory response , which would allow a better control of infections, and the negative side effects accompanying it in terms of inflammation-associated pathologies, such as cardiovascular diseases or cancer. Numerous studies dating as far back as the 1980s have repeatedly shown that vaccination with influenza is associated with a strong reduction in not only pneumoniaor flu-related but surprisingly also all-cause-as well as cardiovascular mortality rates (Barker and Mullooly 1980; Nichol et al. 2003, 2007; Campitelli et al. 2010). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The low percentages of naïve T cells commonly observed in elderly people are thought to be causally associated with mortality, primarily from infectious disease, and are taken as a hallmark of “immunosenescence”. Whether low levels of naive cells actually do associate with mortality has, however, not been tested in longitudinal studies. Here, we present correlations between peripheral T-cell phenotypes and 8-year survival in individuals from the population-based prospective Leiden 85-plus Study. Counter-intuitively, we found that a lower frequency of naïve CD8+ T cells (characterized as CD45RA+CCR7+CD27+CD28+) at baseline (>88 years) correlated with significantly better survival, while there was a tendency for the reciprocal accumulation of late-differentiated effector memory cells (CD45RA−CCR7−CD27−CD28−) also to associate with better survival. These findings suggest that better retention of memory cells specific for previously encountered antigens may provide a survival advantage in this particular population. Given the prevalence of Cytomegalovirus (CMV) and its reported association with immunosenescence, we tested whether memory for this potential pathogen was relevant to survival. We found that individuals mounting an exclusively pro-inflammatory ex vivo response (TNF, IFN-γ, IL-17) to the major CMV target molecules pp65 and IE1 had a significant survival advantage over those also having anti-inflammatory responses (IL-10). These findings suggest that higher levels of naïve T cells may not necessarily be associated with a survival advantage and imply that the nature of immunosurveillance against CMV may be crucial for remaining longevity, at least in the very elderly. Electronic supplementary material The online version of this article (doi:10.1007/s11357-012-9425-7) contains supplementary material, which is available to authorized users.
    Age 06/2012; 35(4). DOI:10.1007/s11357-012-9425-7 · 3.45 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Three achievements are presented: (i) a new communications style in which a subject of interest such as a visual object rendered using TV broadcasting is directly linked with chat messages, (ii) a method of grouping TV viewers who are interested in the same visual object, and (iii) a method of sharing thumbnail images without transmitting the video data itself.
    IEEE Transactions on Consumer Electronics 09/2002; 48(3-48):579 - 583. DOI:10.1109/TCE.2002.1037044 · 1.05 Impact Factor
  • Source

    Aging and Disease 10/2011; 2(5):339-45. · 3.07 Impact Factor
Show more

Similar Publications