Vaccine development for capsulate bacteria causing pneumonia.

Pneumonia strikes the extremes of the age spectrum, causing maximal death and disability in children and the elderly. Despite its worldwide impact, there is a paucity of epidemiologic data regarding its incidence and the causative organisms. The two leading causes of bacterial pneumonia in childhood are Streptococcus pneumoniae (SP) and Haemophilus influenzae type b (Hib). SP is the major cause of pneumonia beyond the newborn period. In neonates, Group B Streptococcus (GBS) remains a major cause of sepsis and pneumonia despite recent reductions due to targeted perinatal antibiotic prophylaxis. Hib vaccine can prevent pneumonia in developing countries. SP conjugate vaccine prevents X-ray confirmed pneumonia in low incident populations, but protection appears more marginal in high incident populations. Non-vaccine SP serotypes have demonstrated increased carriage and mucosal disease, but not invasive disease following vaccination. GBS vaccines are in the early stages of clinical development as prenatal or antenatal vaccines.