The study reported by Simonsen et al1 in the February 14, 2005, issue of the ARCHIVES is counterintuitive to those of us with clinical experience and will surprise many of our public health decision makers. In keeping with best practice guidelines, clinicians have aspired to ever-higher coverage rates for influenza immunization for our older patients. Now it appears that immunizing older patients...makes little or no impression on the commonly encountered flu viruses of the past thirty-plus years, as best as can be discerned from mortality patterns among the elderly. This contrasts with data from other studies, however.2
The immune response of seniors to vaccines is much less intense than it is in the younger population. Perhaps, to actually save the lives of our patients sixty-five years and older, instead of just deluding ourselves that we are doing so, we should take a lesson from the Japanese experience of [a few] decades ago: from 1962 through 1987, schoolchildren were mandated to be vaccinated against influenza, and very high coverage rates were obtained.3 The resultant "herd" (community) immunity led to a marked decline in the rate of excess mortality in the elderly from influenza, pneumonia, and all causes during the period when the vaccination requirement was in effect (when the law was relaxed after 1987, the death rates rose again).
It is well known that children harbor most of the load of communicable influenza virus, acting as vectors for their vulnerable elderly relatives. Also, elderly patients' immune response to influenza vaccination (among others) is reduced compared with younger recipients.
Given that the study3 based on the Japanese data was coauthored by several of the coauthors of the study by Simonsen and colleagues,1 I was surprised that they did not recommend a similar approach, or at least suggest its consideration. Our public health officials should consider this tactic in the effort against influenza in the elderly -- or else boost the antigen titer in influenza vaccine intended for seniors.
Gilbert Ross, M.D.
American Council on Science and Health
1995 Broadway, 2nd floor
New York, NY 10023
(ross[at]acsh.org)
References:
1. Simonsen L, Reichert TA, Viboud C, Blackwelder WC, Taylor RJ, Miller MA. Impact of influenza vaccinations on seasonal mortality in the US elderly population. Arch Intern Med. 2005;165:265-272.
2. Vu T, Farish S, Jenkins M, Kelly H. A meta-analysis of effectiveness of influenza vaccine in persons aged 65 years and over living in the community. Vaccine. 2002;20:1831-1836.
3. Reichert TA, Sugaya N, Fedson DS, Glezen P, Simonsen L, Tashiro M. The Japanese experience with vaccinating schoolchildren against influenza. N Engl J Med. 2001;344:889-896.
