The effectiveness of pneumococcal polysaccharide vaccination in HIV-infected adults: a systematic review

OBJECTIVE: The effectiveness of 23-valent pneumococcal polysaccharide vaccine (PPV-23) in preventing pneumococcal disease in HIV-infected people is a subject of debate. We reviewed the clinical evidence for recommending PPV-23 for use in HIV-infected patients.

METHODS: A systematic search of peer-reviewed publications (EMBASE, the Cochrane Library, and PubMed/BioMed Central), the Internet and grey literature was conducted. Three hundred and eighteen documents were reviewed. Studies reporting risk estimates for all-cause pneumonia, all-pneumococcal disease, and/or invasive pneumococcal disease after PPV-23 immunization in HIV-infected adults were included.

RESULTS: We identified one randomized trial and 15 observational studies. While the randomized trial found a 60% increased risk of all-cause pneumonia among vaccinees, 11 of the 15 observational studies found various degrees of disease protection associated with PPV-23 immunization. However, most studies suffered from limited confounder control in their multivariate analyses, despite study data suggesting substantial differences between the characteristics of exposed and unexposed individuals.

CONCLUSIONS: The current clinical evidence provides only moderate support for PPV-23 immunization of HIV-infected adults. More data are needed on the efficacy of newer conjugated pneumococcal vaccines, which may be more immunogenic and could potentially replace PPV-23 in the future.