Pneumococcal vaccination among HIV-infected adult patients in the era of combination antiretroviral therapy

HIV-infected patients remain at higher risk for pneumococcal disease than the general population despite immune reconstitution and suppression of HIV replication with combination antiretroviral therapy. Vaccination with 23-valent pneumococcal polysaccharide vaccine (PPV23) composed of T-cell-independent antigens has been recommended to reduce the risk of pneumococcal disease in HIV-infected adults. However, given the heterogeneity of study design, execution and subjects enrolled, studies examining serological responses to PPV23 yielded conflicting results and observational studies of clinical effectiveness only provided moderate evidence to support the routine use of PPV23 in HIV-infected adults. Pneumococcal conjugate vaccine (PCV), with conjugation of the capsular polysaccharide to a protein carrier, is more immunogenic than PPV23 and has been demonstrated to protect against pneumococcal disease in HIV-infected children and recurrent invasive pneumococcal disease in HIV-infected adolescents and adults. Guidelines have recently been revised to recommend that HIV-infected patients aged 19 y or older receive one dose of 13-valent pneumococcal conjugate vaccine (PCV13) followed by a booster vaccination with PPV23. In this paper, we review the studies using different vaccination strategies to improve immunogenicity among HIV-infected adult patients.