tetano
Editor, Senior Moderator
PLoS One. 2019 May 23;14(5):e0216983. doi: 10.1371/journal.pone.0216983. eCollection 2019.
[h=1]Influenza vaccination in the elderly: 25 years follow-up of a randomized controlled trial. No impact on long-term mortality.[/h] Verhees RAF[SUP]1[/SUP], Thijs C[SUP]2[/SUP], Ambergen T[SUP]3[/SUP], Dinant GJ[SUP]1[/SUP], Knottnerus JA[SUP]1[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Influenza vaccination is proven effective in preventing influenza. However, long-term effects on mortality have never been supported by direct evidence. In this study we assessed the long-term outcome of influenza vaccination on mortality in the elderly by conducting a 25-year follow-up study of a RCT on the efficacy of influenza vaccination as baseline. The RCT had been conducted in the Netherlands 5 years before vaccination was recommended for those aged >65 and 17 years before recommending it for those aged >60. The RCT included 1838 community-dwelling elderly aged ≥ 60 that had received an intramuscular injection with the inactivated quadrivalent influenza vaccine (n = 927) or placebo (n = 911) during the 1991/1992 winter. In our follow-up study, outcomes included all-cause mortality, influenza-related mortality and seasonal mortality. Unadjusted and adjusted hazard ratios (HRs) were estimated by Cox regression and sub-hazard ratios (SHRs) by competing risk models. Secondary analyses included subgroup analyses by age and disease status. The vital status up to January 1, 2017 was provided in 1800/1838 (98%) of the cases. Single influenza vaccination did not reduce all-cause mortality when compared to placebo (adjusted HR 0.95, 95% CI 0.85-1.05). Also, no differences between vaccination and placebo group were shown for underlying causes of death or seasonal mortality. In those aged 60-64, median survival increased with 20.1 months (95% CI 2.4-37.9), although no effects on all-cause mortality (adjusted HR 0.86, 95% CI 0.72-1.03) could be demonstrated in survival analysis. In conclusion, this study did not demonstrate a statistically significant effect following single influenza vaccination on long-term mortality in community-dwelling elderly in general. We propose researchers designing future studies on influenza vaccination in the elderly to fit these studies for longer-term follow-up, and suggest age-group comparisons in observational research. Clinical trial registry number: NTR6179.
PMID: 31120943 DOI: 10.1371/journal.pone.0216983
[h=1]Influenza vaccination in the elderly: 25 years follow-up of a randomized controlled trial. No impact on long-term mortality.[/h] Verhees RAF[SUP]1[/SUP], Thijs C[SUP]2[/SUP], Ambergen T[SUP]3[/SUP], Dinant GJ[SUP]1[/SUP], Knottnerus JA[SUP]1[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] Influenza vaccination is proven effective in preventing influenza. However, long-term effects on mortality have never been supported by direct evidence. In this study we assessed the long-term outcome of influenza vaccination on mortality in the elderly by conducting a 25-year follow-up study of a RCT on the efficacy of influenza vaccination as baseline. The RCT had been conducted in the Netherlands 5 years before vaccination was recommended for those aged >65 and 17 years before recommending it for those aged >60. The RCT included 1838 community-dwelling elderly aged ≥ 60 that had received an intramuscular injection with the inactivated quadrivalent influenza vaccine (n = 927) or placebo (n = 911) during the 1991/1992 winter. In our follow-up study, outcomes included all-cause mortality, influenza-related mortality and seasonal mortality. Unadjusted and adjusted hazard ratios (HRs) were estimated by Cox regression and sub-hazard ratios (SHRs) by competing risk models. Secondary analyses included subgroup analyses by age and disease status. The vital status up to January 1, 2017 was provided in 1800/1838 (98%) of the cases. Single influenza vaccination did not reduce all-cause mortality when compared to placebo (adjusted HR 0.95, 95% CI 0.85-1.05). Also, no differences between vaccination and placebo group were shown for underlying causes of death or seasonal mortality. In those aged 60-64, median survival increased with 20.1 months (95% CI 2.4-37.9), although no effects on all-cause mortality (adjusted HR 0.86, 95% CI 0.72-1.03) could be demonstrated in survival analysis. In conclusion, this study did not demonstrate a statistically significant effect following single influenza vaccination on long-term mortality in community-dwelling elderly in general. We propose researchers designing future studies on influenza vaccination in the elderly to fit these studies for longer-term follow-up, and suggest age-group comparisons in observational research. Clinical trial registry number: NTR6179.
PMID: 31120943 DOI: 10.1371/journal.pone.0216983