Clinical experience of the 23-valent capsular polysaccharide pneumococcal vaccination in HIV-1-infected patients receiving highly active antiretroviral therapy: a prospective observational study

To assess the impact of vaccination with 23-valent pneumococcal polysaccharide vaccine on the risks for development of pneumococcal disease, all-cause community-acquired pneumonia, HIV progression, and mortality and immunologic and virologic responses among HIV-1-infected patients treated with highly active antiretroviral therapy (HAART), we conducted a 2-year prospective observational cohort study at a university hospital in Taiwan. A total of 305 HIV-1-infected patients who received 23-valent pneumococcal vaccine (vaccinees) and 203 patients who did not (non-vaccinees) were prospectively observed between 1 June 2000 and 31 October 2002. Changes of CD4+ and plasma viral load (PVL) from baseline to week 4 of vaccination were assessed in 31 randomly selected vaccinees. The incidence of pneumococcal disease and bacteremia of vaccinees was 2.1 per 1000 patient-years (PY) (95% confidence interval (95% CI), 1.7–2.5 per 1000 PY) over the median observation of 641 days (range, 37–832 days) following vaccination while that of non-vaccinee was 21.8 per 1000 PY (95% CI, 20.1–23.7 per 1000 PY) and 7.3 per 1000 PY (95% CI, 7.0–7.6 per 1000 PY), respectively, over the observation of 500 days (range, 32–851 days), with an adjusted odds ratio (AOR) for developing pneumococcal disease of 0.085 (95% CI, 0.010–0.735) and for bacteremia of 0.22 (95% CI, 0.018–2.561). The median CD4+ count increased by 45×106 l−1 (P=0.01) and median PVL change was 0 log10 copies/ml (range of decrease, −0.74 to 2.47 log10 copies/ml) after 1 month of pneumococcal vaccination among the subgroup of 31 vaccinees receiving HAART. The median CD4+ count increase from baseline to the end of study was 149×106 l−1 for vaccinees and 107×106 l−1 for non-vaccinees (P=0.21). The AOR of developing all-cause community-acquired pneumonia and new AIDS-defining opportunistic illnesses (OI) of vaccinees as compared to non-vaccinees was 1.876 (95% CI, 0.785–4.485) and 0.567 (95% CI, 0.217–1.484), respectively. Death rate of vaccinees and non-vaccinees was 17.7 per 1000 PY (95% CI, 16.5–18.9 per 1000 PY) and 80.5 per 1000 PY (95% CI, 77.1–83.9 per 1000 PY), respectively. Adjusted hazard ratio for death of vaccinees as compared with non-vaccinees was 0.733 (95% CI, 0.236–2.274). Our data suggested that vaccination with 23-valent pneumococcal polysaccharide vaccine and receipt of HAART were associated with reduced risks for pneumococcal disease among HIV-1-infected patients receiving HAART. Vaccination did not increase the risks of all-cause community-acquired pneumonia, HIV progression, and mortality. Vaccination did not increase PVL or decrease CD4+ among HIV-1-infected patients receiving HAART.