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Comment & Response
April 2014

The Importance of Influenza Vaccination—Reply

Author Affiliations
  • 1Department of Pharmaceutical Health Services Research, University of Maryland School of Pharmacy, Baltimore
JAMA Intern Med. 2014;174(4):645-646. doi:10.1001/jamainternmed.2013.11170

In Reply My article aimed to show that many basic assumptions and claims underlying the annual campaign to vaccinate against influenza do not stand up to critical review.1 I am grateful that the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA) responded to my article, but disappointed that they did not examine the data underlying their positions, which are to my knowledge consistent with those of the Centers for Disease Control and Prevention (CDC)—and equally problematic.

The IDSA and SHEA make 4 major criticisms. First, they emphasize that influenza is a significant illness, causing more than 12 000 hospitalizations last year. I do not think 12 000 hospitalizations (approximately 0.03% of the 35 million annual US hospitalizations2) by itself qualifies influenza as a major public health threat. Influenza can indeed lead to severe complications including death, but my article attempted to counter the popular impression that we are all at risk of serious complications of influenza by pointing out that the majority of people do not annually contract influenza, and for most of those who do, it is self-limiting and tragedies are rare.

Second is the question of vaccine performance. I argued that there is no good evidence that vaccines can prevent hospitalizations and death. There are no adequately powered randomized trials of influenza vaccines in the elderly to detect any possible effect on these outcomes, and serious methodological problems have been documented in the available nonrandomized studies that report impressive benefit. But IDSA and SHEA assert that vaccinations averted 112 900 US hospitalizations during 2005 through 2011, citing a recent CDC publication.3 This article, however, did not present any new evidence of vaccine effectiveness against hospitalization. Rather, it estimated averted hospitalizations by taking previously published estimates of vaccine efficacy against influenza cases and extrapolating this effect to influenza hospitalizations. But there is no good reason to believe a 20% reduction in cases would neatly translate into a 20% reduction in hospitalizations. Individuals with influenza vary in their risk of complications. For example, averting cases among a more healthy elderly population may do little to reduce the number of hospitalizations that occur more frequently among less healthy elderly individuals.

Third, IDSA and SHEA state that “vaccine safety is monitored closely in the United States” and the cases of narcolepsy in Sweden and Finland and febrile convulsions in Australia were identified by postmarketing surveillance. I disagree. It is at odds with the Ministerial review in Australia, which concluded the following: “This Review has revealed an adverse event reporting system that is not robust or timely and which does not conform to WHO [World Health Organization] recommendations….”4(p6) More importantly, even had surveillance identified these harms, it does not change the fact that serious and unanticipated harms from influenza vaccines have occurred.

Finally, of course vaccines and hand washing can be complementary. But without head-to-head trials, IDSA and SHEA’s claim that vaccines are “best”5 (ie, better than other interventions) lacks evidence.

Physicians and the public expect officials and professional societies to critically assess the evidence on which they are basing their statements and recommendations. We are ill served by authorities that do otherwise.

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Article Information

Corresponding Author: Peter Doshi, PhD, Department of Pharmaceutical Health Services Research, University of Maryland School of Pharmacy, 220 Arch St, 12th Floor, Baltimore, MD 21201 (pdoshi@rx.umaryland.edu).

Conflict of Interest Disclosures: Dr Doshi is a corecipient of a UK National Institute for Health Research grant to carry out a Cochrane review of neuraminidase inhibitors (http://www.hta.ac.uk/2352). In addition, Dr Doshi received €1500 from the European Respiratory Society in support of his travel to the society’s September 2012 annual congress, where he gave an invited talk on oseltamivir.

Doshi  P.  Influenza vaccines: time for a rethink.  JAMA Intern Med. 2013;173(11):1014-1016.PubMedGoogle ScholarCrossref
US Centers for Disease Control and Prevention. Hospital utilization (in non-Federal short-stay hospitals). 2013. http://www.cdc.gov/nchs/fastats/hospital.htm. Accessed August 27, 2013.
Kostova  D, Reed  C, Finelli  L,  et al.  Influenza illness and hospitalizations averted by influenza vaccination in the United States, 2005-2011.  PLoS One. 2013;8(6):e66312.PubMedGoogle ScholarCrossref
Stokes  B. Ministerial review into the public health response into the adverse events to the seasonal influenza vaccine. Department of Health, Government of Western Australia; July 2010. http://www.health.wa.gov.au/publications/documents/Stokes_Report.pdf. Accessed August 18, 2010.
Infectious Diseases Society of America. What is seasonal influenza? 2013. http://www.idsociety.org/What_is_Seasonal_Influenza. Accessed August 27, 2013.