Pneumonia is an inflammation of the lungs caused by bacteria, viruses or chemical irritants. It is a serious infection in which air sacs in the lungs fill with pus and other liquid.

  • Pneumonia may be lobar (affects one or more sections—lobes—of the lungs) or bronchial (affects patches throughout both lungs, also called “bronchopneumonia”).

  • Pneumonia is most common in winter and spring.

  • Pneumonia affects more boys than girls.

  • About 10 to 15 percent of children with a respiratory infection have pneumonia.

Researchers at Boston Children's Hospital and Harvard School of Public Health have discovered a new mechanism of immunity that suggests that there may be a better way to protect vulnerable children and adults against Streptococcus pneumoniae (pneumococcal) infection, which leads to serious illnesses, including pneumonia and meningitis (inflammation of the brain). The current vaccine, Prevnar, is expensive and covers only seven of the 91 known pneumococcal strains.