Pneumococcal disease: Under the pressure of vaccination

Streptococcus pneumoniae (pneumococcus) infection, a serious global problem that is the leading cause of pneumonia and other life-threatening illnesses, is vaccine preventable. This gram-positive bacterium has more than 90 known serotypes and 46 serogroups determined by the specific bacterium’s capsule polysaccharide composition. Humans can spread this bacteria via airborne droplets through coughing, sneezing, and even a bout of uncontrollable laughter. All serotypes may cause disease—especially otitis media (OM), sinusitis, and bronchitis. A comparatively limited number of serotypes tend to enter the body through sterile environments, such as blood, cerebrospinal fluid, pleural fluid, joint fluid, or pericardial fluid. These more serious cases are considered invasive pneumococcal disease (IPD). The Centers for Disease Control and Prevention’s Active Bacterial Core Surveillance tracks IPD data, which indicate that IPD occurs most often in the very young and the elderly. Pneumococcal vaccines Since 2000, routine childhood pneumococcal conjugate vaccine has decreased rates of IPD caused by pneumococcal serotypes...