['To study the effectiveness of the Haemophilus influenzae type b (Hib) vaccination program in Uganda.', 'Case-control study of Hib vaccine effectiveness against Hib meningitis. Cases were children hospitalized with Hib meningitis confirmed by culture and/or latex agglutination. Cases were identified retrospectively from July 2002 to July 2004, and prospectively from July 2004 to July 2005. Each case-patient was matched by age to three neighbourhood and three hospital controls; all children were eligible to receive Hib vaccine through the routine schedule. Vaccine effectiveness was evaluated by conditional logistic regression, controlling for confounding variables.', 'We enrolled 41 cases; their median age was 6 months. Only six (15%) cases, all HIV-negative, had received >/=2 doses of Hib vaccine, compared with 64% of neighbourhood controls and 70% of hospital controls. Controlling for maternal education, the only variable which remained in the multivariable model, vaccine effectiveness for two or three doses vs. no dose was 99% [95% confidence intervals (CI) 92-100%] and 96% (95% CI 80-100%) when cases were compared with neighbourhood and hospital controls, respectively.'] Is haemophilus influenzae type b conjugate vaccine highly effective in the Ugandan routine immunization program : a case-control study?