SummaryBackgroundHaemophilus influenzae type b (Hib) conjugate vaccine reduces the risk of pneumonia in infants.ObjectiveTo determine the effect of Hib conjugate vaccine (HibCV) on the prevention of pneumonia as a complication among infants hospitalized for bronchiolitis.MethodsThis record-based case–control study was conducted at The Children's Hospital “Dr. Ovidio Aliaga U” in La Paz, Bolivia during 2003 and 2004. Cases were infants hospitalized for bronchiolitis under 1 year of age who developed radiological pneumonia during hospitalization. Controls were patients who had good clinical progress without the use of antibiotics. Pneumonia was defined by alveolar consolidation on chest X-ray that justified the use of antibiotics.ResultsEighty patients were studied (16 cases and 64 controls). Their median age was 4.5 months. Demographic and clinical features were similar in both groups, except for a higher proportion of vomiting (56.3% vs. 28.1%; p
