Pneumococcal Vaccination in Older Adults

Abstract

Jackson et al. (May 1 issue)¹ demonstrate that the polysaccharide pneumococcal vaccine did not reduce the incidence of pneumonia among older adults — a finding that is consistent with the results of the previous blinded, randomized, controlled trials.² The authors assert, however, that vaccination should nevertheless continue, because a study³ calculated that it is cost effective in preventing pneumococcal bacteremia in persons in this age group. That report, however, tacitly assumed that a reduction in the frequency of pneumococcal bacteremia among vaccinees translated into a decrease in the frequency of pneumonia — a premise that the current study and the previous randomized trials refute. The appropriate comparison in terms of cost analysis is that between the expenses associated with hospitalization for pneumococcal bacteremia among unimmunized persons and the combined expenses associated with immunization plus an equivalent number of hospitalizations among vaccinees for pneumonias without pneumococcal bacteremia. A reexamination of the estimates demonstrates that such a calculation would not justify vaccination for the prevention of pneumococcal bacteremia.