Anti-pneumococci vaccination:: role and indications in the prevention of community acquired infections of the lower respiratory tract.

Objective - The authors had for aim to evaluate the effectiveness and clinical indications of the anti pneumococcal vaccine. Methods - Seventy one articles were selected after a computerized research including the most recent studies on immunogenicity, all the prospective double blind randomized trials, and retrospective studies (case-control and indirect cohort studies). The evaluation concerned exclusively non conjugated vaccine. Results - The immune response was significant among vaccinated patients including elderly ones; antibody response was reduced or absent among immune-compromised patients. Only one study among 11 randomized trials concerned the 23-valent vaccine. According to the results of these trials and of 2 meta-analyses, efficacy in preventing pneumococcal bacteremia and pneumococcal pneumonia is clearly established in young adults (with a response rate reaching around 80% for vaccine serotypes). Clinical studies in older adults, adults with risk factors, or immune-compromised adults are inconclusive, usually because the number of patients was too small. Retrospective case-control and indirect cohort studies confirmed the clinical efficiency of pneumococcal vaccination. They showed that pneumococcal vaccination was efficient in 50-80% of the patients to prevent invasive pneumococcal diseases, including in older patients and those with associated diseases, particularly with COPD or cardiovascular diseases. Efficiency was not demonstrated in immune-compromised patients. The vaccine proved safe with a good tolerance. Vaccination is recommended by the WHO and various advisory national committees in North America and Europe for elderly patients and those with associated diseases. (C) 2001 Editions scientifiques et medicales Elsevier SAS.