Influenza vaccination of health care workers
============================================

* Michael T. Osterholm
* Nicholas S. Kelley

Although we strongly support increasing influenza vaccination of health care workers, we believe that guidance supporting this effort should be based on scientifically sound evidence regarding influenza vaccine effectiveness and the subsequent disease reduction in influenza workers and their patients. The editorial by Flegel contains factual errors, and the data cited to support the case for health care worker vaccination are problematic.1

The vaccine efficacy rate of “about 86% when the circulating strain and vaccine strain are well matched” is not an accurate statement, and the reference provided does not support that conclusion.1,2 We recently conducted a comprehensive meta-analysis of influenza vaccine efficacy and effectiveness and found that the trivalent inactivated vaccine provides approximately 59% protection in healthy younger adults and that match did not significantly affect how well the vaccine protected against influenza.3 Additionally, we found that the perception that current influenza vaccines provide such high levels of protection is a major barrier to developing novel-antigen, game-changing vaccines.4

Also, the 4 randomized controlled trials cited in reference 5 do not provide strong evidence to support an impact on patient mortality when increased numbers of health care workers are vaccinated.5 In fact, 2 of the studies do not support this claim,6,7 and the other 2 only weakly support it.8,9

The cost savings report cited10 (reference6 in the editorial) uses the 2006 HICPAC statement as the source for these cost savings, but those numbers are not present in that report.11 Additionally, most cost-effectiveness numbers are based on overestimated vaccine efficacy and need to be revised.4

Last, there is no process for selecting influenza vaccine strains that reduces the risk of Guillain-Barré syndrome (GBS), as the reason influenza vaccine causes GBS is still unclear.

## References

1.  Flegel K. Health care workers must protect patients from influenza by taking the annual vaccine. CMAJ 2012;184:1873.
    
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2.  Thomas RE, Jefferson T, Demicheli V, et al. Influenza vaccination for healthcare workers who work with the elderly [review]. Cochrane Database Syst Rev 2006;(3):CD005187.
    
    

3.  Osterholm MT, Kelley NS, Sommer A, et al. Efficacy and effectiveness of influenza vaccines: a systematic review and meta-analysis. Lancet Infect Dis 2012;12:36–44.
    
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4.  Osterholm MT, Kelley NS, Manske JM, et al. The Compelling need for game-changing influenza vaccines: an analysis of the influenza vaccine enterprise and recommendations for the future. Minneapolis (MN): Center for Infectious Disease research & Policy; 2012. Available: [www.cidrap.umn.edu/cidrap/files/80/ccivi%20report.pdf](http://www.cidrap.umn.edu/cidrap/files/80/ccivi%20report.pdf) (accessed 2012 Oct. 31)
    
    

5.  Talbot TR, Babcock H, Caplan AL, et al. Revised SHEA position paper: influenza vaccination of healthcare personnel. Infect Control Hosp Epidemiol 2010;31:987–95.
    
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6.  Potter J, Stott DJ, Roberts MA, et al. Influenza vaccination of health care workers in long-term-care hospitals reduces the mortality of elderly patients. J Infect Dis 1997;175:1–6.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NzoiamluZmRpcyI7czo1OiJyZXNpZCI7czo3OiIxNzUvMS8xIjtzOjQ6ImF0b20iO3M6MjI6Ii9jbWFqLzE4NS8yLzE1MC4yLmF0b20iO31zOjg6ImZyYWdtZW50IjtzOjA6IiI7fQ==) 

7.  Carman WF, Elder AG, Wallace LA, et al. Effects of influenza vaccination of health-care workers on mortality of elderly people in long-term care: a randomised controlled trial. Lancet 2000;355:93–7.
    
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8.  Hayward AC, Harling R, Wetten S, et al. Effectiveness of an influenza vaccine programme for care home staff to prevent death, morbidity, and health service use among residents: cluster randomised controlled trial. BMJ 2006;333:1241.
    
    [Abstract/FREE Full Text](http://www.cmaj.ca/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6MzoiYm1qIjtzOjU6InJlc2lkIjtzOjEzOiIzMzMvNzU4MS8xMjQxIjtzOjQ6ImF0b20iO3M6MjI6Ii9jbWFqLzE4NS8yLzE1MC4yLmF0b20iO31zOjg6ImZyYWdtZW50IjtzOjA6IiI7fQ==) 

9.  Lemaitre M, Meret T, Rothan-Tondeur M, et al. Effect of influenza vaccination of nursing home staff on mortality of residents: a cluster-randomized trial. J Am Geriatr Soc 2009;57:1580–6.
    
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10. Steckel CM. Mandatory influenza immunization for health care workers: an ethical discussion. AAOHN J 2007;55:34–9.
    
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11. Pearson ML, Bridges C, Harper S, et al. Influenza vaccination of health-care personnel: recommendations of the Healthcare Infection Control Practices Advisory Committee (HICPAC) and the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 2006;55(RR-2):1–16.
    
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