Bacterial, community-acquired pneumonia classically show lung consolidation of one lung segmental lobe, which is known as lobar pneumonia.

In 1998, WHO noted that: "Wherever thorough studies have been performed, Hib has been shown to be an important cause of childhood meningitis and a major cause of bacterial pneumonia in children."

Nonetheless, since influenza is often complicated by secondary bacterial infection of the lungs, antibiotics could be life-saving in the case of late-onset pneumonia.