This Article  • Full text  • PDF  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citation map  • Citing articles on HighWire  • Citing articles on ISI (3)  • Contact me when this article is cited  Related Content  • Related articles  • Similar articles in this journal  Topic Collections  • Immunization  • Viral Infections  • Aging/ Geriatrics  • Alert me on articles by topic

	Since this article does not have an abstract, we have provided the first 150 words of the full text and any section headings.

In an intriguing study published in the ARCHIVES, Simonsen and colleagues¹ conclude that observational studies have substantially overestimated influenza vaccination benefit in people 65 years and older. After adjusting for an aging US population and the frequency of influenza seasons in which the apparently more virulent influenza A(H3N2) subtype was dominant, they found that fewer than 10% of all winter deaths among people 65 years and older were attributable to influenza. That was not consistent with the meta-analysis estimate of vaccine effectiveness for all-cause mortality of 50% (45%-56%),² which clearly suggests a much higher contribution of influenza as a cause of mortality.

This apparent discrepancy may be partly explained by different approaches to assessing vaccine impact. In the meta-analysis, vaccine effectiveness was only estimated for years when the vaccine and circulating strains were matched.² Simonsen and colleagues¹ have used all years in their study, necessarily including mismatched years . . . [Full Text of this Article]

AUTHOR INFORMATION
Heath Kelly, BSc, MBBS, MPH, FAFPHM; Trang Vu, BSc, MPH, MHSc; David Smith, BMedSc, MBBS, FRCPA

RELATED ARTICLES

Impact of Influenza Vaccination on Seasonal Mortality in the US Elderly Population
Lone Simonsen, Thomas A. Reichert, Cecile Viboud, William C. Blackwelder, Robert J. Taylor, and Mark A. Miller
Arch Intern Med. 2005;165(3):265-272.
ABSTRACT | FULL TEXT  

The efficacy of influenza vaccination in elderly individuals. A randomized double-blind placebo-controlled trial
T. M. Govaert, C. T. Thijs, N. Masurel, M. J. Sprenger, G. J. Dinant, and J. A. Knottnerus
JAMA. 1994;272(21):1661-1665.
ABSTRACT  

THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES

Influenza vaccination as model for testing immune modulation induced by anti-TNF and methotrexate therapy in rheumatoid arthritis patients
Kapetanovic et al.
Rheumatology (Oxford) 2007;46:608-611.
ABSTRACT | FULL TEXT