PNEUMOCOCCAL POLYSACCHARIDE VACCINE EFFICACY - AN EVALUATION OF CURRENT RECOMMENDATIONS

Objective.-To determine pneumococcal polysaccharide vaccine efficacy i n selected populations at risk for serious pneumococcal infection for whom vaccination is currently recommended and to assess duration of pr otection after vaccination. Design.-Vaccine efficacy was estimated usi ng indirect cohort analysis to compare the proportion of pneumococcal infections caused by serotypes included in the vaccines of vaccinated and unvaccinated persons who were identified during 14 years of nation al surveillance. Setting.-Hospital laboratories in the United States t hat submitted pneumococcal isolates to the Centers for Disease Control and Prevention between May 1978 and April 1992. Participants.-A total of 2837 persons older than 5 years who had pneumococcus isolated from blood or cerebrospinal fluid. Results.-Overall efficacy for preventin g infection caused by serotypes included in the vaccine was 57% (95% c onfidence interval [CI], 45% to 66%). Efficacy among persons with diab etes mellitus was 84% (95% CI, 50% to 95%); with coronary vascular dis ease, 73% (95% CI, 23% to 90%); with congestive heart failure, 69% (95 % CI, 17% to 88%); with chronic pulmonary diseases, 65% (95% CI, 26% t o 83%); and with anatomic asplenia, 77% (95% CI, 14% to 95%). Efficacy was not documented for patients with alcoholism or cirrhosis, sickle cell disease, chronic renal failure, lymphoma, leukemia, or multiple m yeloma, although sample sizes were small for these groups. Efficacy fo r immunocompetent persons older than 65 years was 75% (95% CI, 57% to 85%). Efficacy did not decline with increasing interval after vaccinat ion: 5 to 8 years after vaccination it was 71% (95% CI, 24% to 89%), a nd 9 years or more after vaccination it was 80% (95% CI, 16% to 95%). Conclusions.-Intensified efforts to improve pneumococcal vaccine cover age among certain populations for whom vaccination is currently recomm ended is indicated, but universal revaccination is not warranted at th is time.