Effects of influenza vaccination of health-care workers on mortality of elderly people in long-term care: A randomised controlled trial

The University of Edinburgh, Edinburgh, Scotland, United Kingdom
The Lancet (Impact Factor: 45.22). 02/2000; 355(9198):93-7. DOI: 10.1016/S0140-6736(99)05190-9
Source: PubMed


Vaccination of health-care workers has been claimed to prevent nosocomial influenza infection of elderly patients in long-term care. Data are, however, limited on this strategy. We aimed to find out whether vaccination of health-care workers lowers mortality and the frequency of virologically proven influenza in such patients.
In a parallel-group study, health-care workers in 20 long-term elderly-care hospitals (range 44-105 patients) were randomly offered or not offered influenza vaccine (cluster randomisation, stratified for policy for vaccination of patients and hospital size). All deaths among patients were recorded over 6 months in the winter of 1996-97. We selected a random sample of 50% of patients for virological surveillance for influenza, with combined nasal and throat swabs taken every 2 weeks during the epidemic period. Swabs were tested by tissue culture and PCR for influenza viruses A and B.
Influenza vaccine uptake in health-care workers was 50.9% in hospitals in which they were routinely offered vaccine, compared with 4.9% in those in which they were not. The uncorrected rate of mortality in patients was 102 (13.6%) of 749 in vaccine hospitals compared with 154 (22.4%) of 688 in no-vaccine hospitals (odds ratio 0.58 [95% CI 0.40-0.84], p=0.014). The two groups did not differ for proportions of patients positive for influenza infection (5.4% and 6.7%, respectively); at necropsy, PCR was positive in none of 17 patients from vaccine hospitals and six (20%) of 30 from no-vaccine hospitals (p=0.055).
Vaccination of health-care workers was associated with a substantial decrease in mortality among patients. However, virological surveillance showed no associated decrease in non-fatal influenza infection in patients.

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    • "Influenza immunization is approximately 60% effective in preventing infection in healthy adults, and also reduces the duration and severity of symptoms when infection occurs [1]. Vaccination of HCW is associated with a reduced mortality in chronic care/long term care homes, as shown in randomized control trials [2] [3] [4] [5], and with reduced hospital-acquired infections in acute care although these studies are of lower quality [6]. "
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    ABSTRACT: A new policy requiring staff in clinical areas to vaccinate or wear a mask was implemented in British Columbia (BC) in the 2012/13 winter. This review assessed the impact of the policy on absenteeism in health care workers. A retrospective cohort study of full-time HCW that worked prior to and during the 2012/13 influenza season in a health authority in BC. The rate of absenteeism due to all cause illness was compared between vaccinated and unvaccinated staff controlling for behaviors outside influenza season. Of the 10079 HCW, 77% were vaccinated. By comparison to absenteeism rates in the pre-influenza season, unvaccinated staff in winter had twice the increase in absenteeism due to all-cause illness than vaccinated staff. After controlling for baseline differences between those vaccinated and unvaccinated, influenza vaccination was associated with reduced absenteeism, saving the Health Authority substantial money. Having regular staff in attendance increases the quality of care. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
    Vaccine 02/2015; 12(13). DOI:10.1016/j.vaccine.2015.01.048 · 3.62 Impact Factor
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    • "The Cochrane review, however, did not take influenza like illness (ILI) and all-cause mortality of residents into consideration, The impact of vaccinating HCWs has been discussed in several articles. Potter [13] and Carman [14] took ILI into consideration in their studies and found a significant association between HCWs’ vaccination against influenza and reduced rates of mortality in residents of NHs, showing how important it is to vaccinate HCWs. HCW absence from work owing to influenza is another important issue and has been studied by several authors [13,15-17]. "
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    ABSTRACT: Background WHO has set a goal of 75% vaccination coverage (VC) for seasonal influenza for residents and also recommends immunization for all healthcare workers (HCWs) in nursing homes (NHs). We conducted a cross-sectional study to estimate the VC for seasonal influenza vaccination in Norwegian NHs in 2012/2013 since the VC in NHs and HCWs is unknown. Methods We gathered information from NHs concerning VC for residents and HCWs, and vaccination costs for HCWs, using a web-based questionnaire. We calculated VC among NH residents by dividing the number of residents vaccinated by the total number of residents for each NH. VC among HCWs was similarly calculated by dividing the number of HCWs vaccinated by the total number of HCWs for each NH. The association between VC and possible demographic variables were explored. Results Of 910 NHs, 354 (38.9%) responded. Median VC per NH was 71.7% (range 0-100) among residents and 0% (range 0-100) among HCWs, with 214 (60%) NHs reporting that none of their HCWs was vaccinated. Median VC for HCWs in NHs with an annual vaccination campaign was 0% (range 0-53), compared to when they did not have an annual vaccination campaign 0% (range 0-12); the distributions in the two groups differed significantly (Mann–Whitney U, P = 0.006 two tailed). Conclusion Median influenza VC in Norwegian NHs was marginally lower than recommended among residents and exceptionally low among HCWs. The VC in HCWs was significantly higher when NHs had an annual vaccination campaign. We recommend that NHs implement measures to increase VC among residents and HCWs, including vaccination campaigns and studies to identify potential barriers to vaccination.
    BMC Public Health 05/2014; 14(1):434. DOI:10.1186/1471-2458-14-434 · 2.26 Impact Factor
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    • "However, the vaccination of HCWs against influenza is indicated not only for the personal protection of the vaccinated HCWs but also because it contributes to the prevention of influenza among unvaccinated persons in their environment, including their patients and family members [14-17]. A number of studies demonstrated that influenza vaccination of HCWs lowers morbidity and mortality in their patients [15-18]. "
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    ABSTRACT: Healthcare workers (HCWs) are at an increased risk of exposure to and transmission of infectious diseases. Vaccination lowers morbidity and mortality of HCWs and their patients. To assess vaccination coverage for influenza and hepatitis B virus (HBV) among HCWs in Croatian hospitals, we conducted yearly nationwide surveys. From 2006 to 2011, all 66 Croatian public hospitals, representing 43--60% of all the HCWs in Croatia, were included. Statistical analysis was performed using the Kruskal--Wallis analysis of variance, Dunn's multiple comparison analysis and the chi-square test, as appropriate. The median seasonal influenza vaccination coverage rates in pre-pandemic (2006--2008) seasons were 36%, 25% and 29%, respectively. By occupation, influenza vaccination rates among physicians were 33 +/- 21%, 33 +/- 22% among graduate nurses, 30--34% among other HCWs, 26 +/- 21% among housekeeping and the lowest, 23 +/- 17%, among practical nurses (p < 0.01). In 2009--2010 season, seasonal influenza vaccination coverage was 30%, while overall vaccination coverage against pandemic influenza was fewer than 5%. Median vaccination coverage in the post-pandemic seasons of 2010--2011 and 2011--2012 decreased to 15% and 14%, respectively (reduction of 24% and 35%, respectively, p < 0.0001). Meanwhile, the median mandatory HBV vaccination coverage was 98%, albeit with considerable differences according to work setting (range 19--100%) and occupation (range 4--100%). We found substantial year-on-year variations in seasonal influenza vaccination rates, with reduction in post pandemic influenza seasons. HBV vaccination is satisfactory compared to seasonal influenza vaccination coverage, although substantial variations by occupation and work setting were observed. These findings highlight the need for national strategies that optimize vaccination coverage among HCWs in Croatian hospitals. Further studies are needed to establish the potential role of mandatory vaccination for seasonal influenza.
    BMC Infectious Diseases 11/2013; 13(1):520. DOI:10.1186/1471-2334-13-520 · 2.61 Impact Factor
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