Streptococcus pneumoniae is a leading and serious
coinfection in adults with human immunodeficiency virus (
HIV) infection, particularly in Africa. Prevention of this disease by vaccination with the current 23-valent
polysaccharide vaccine is suboptimal.
Protein conjugate vaccines offer a further option for protection, but data on their clinical efficacy in adults are needed.
METHODS: In this double-blind, randomized, placebo-controlled clinical efficacy trial, we studied the efficacy of a 7-valent conjugate
pneumococcal vaccine in predominantly HIV-infected Malawian adolescents and adults who had recovered from documented invasive
pneumococcal disease. Two doses of
vaccine were given 4 weeks apart. The primary end point was a further episode of
pneumococcal infection caused by
vaccine serotypes or serotype 6A.
RESULTS: From February 2003 through October 2007, we followed 496 patients (of whom 44% were male and 88% were HIV-seropositive) for 798 person-years of observation. There were 67 episodes of
pneumococcal disease in 52 patients, all in the HIV-infected subgroup. In 24 patients, there were 19 episodes that were caused by
vaccine serotypes and 5 episodes that were caused by the 6A serotype. Of these episodes, 5 occurred in the
vaccine group and 19 in the placebo group, for a
vaccine efficacy of 74% (95% confidence interval [CI], 30 to 90). There were 73 deaths from any cause in the
vaccine group and 63 in the placebo group (hazard ratio in the
vaccine group, 1.18; 95% CI, 0.84 to 1.66). The number of serious adverse events within 14 days after vaccination was significantly lower in the
vaccine group than in the placebo group (3 vs. 17, P = 0.002), and the number of minor adverse events was significantly higher in the
vaccine group (41 vs. 13, P = 0.003).
CONCLUSIONS: