Effectiveness of the polysaccharide pneumococcal vaccine among HIV-infected persons in Brazil: a case control study

BACKGROUND Polysaccharide pneumococcal vaccine is recommended for use in HIV-infected adults in Brazil but there is uncertainty about its effectiveness in this patient population. The main objective of this study was to assess the effectiveness of the 23-valent polysaccharide pneumococcal vaccine against invasive pneumococcal infection among HIV-infected adult patients in São Paulo, Brazil. METHODS A case-control study of 79 cases and 242 controls matched on CD4+ cell count and health care setting was conducted. Among HIV-infected adults in São Paulo, Brazil, with and without S. pneumoniae recovered from a normally sterile site; prior receipt of 23 valent polysaccharide pneumococcal vaccine was determined by review of medical records and patient interview. RESULTS After adjustment for confounding factors, the point estimate for the effectiveness of 23 valent polysaccharide vaccine among HIV-infected adults against all invasive pneumococcal infection was 18% (95% CI: <0 to 62%). CONCLUSION We were unable to demonstrate a statistically significant protective effect of 23 valent polysaccharide against invasive pneumococcal infection vaccine among HIV-infected adults in Brazil.While the vaccine is relatively inexpensive and safe, its effectiveness among HIV-infected adults in Brazil is uncertain.