An update on the "old man's friend"

The flu and pneumococcal vaccines provide some protection against it, but pneumonia is still a major cause of death.

Pneumonia is inflammation deep inside the lungs caused by some kind of infection. As a result of the infection and the immune response to it, the tiny air sacs (alveoli) — where oxygen is absorbed into the bloodstream — fill with fluid, impairing the ability to breathe. Each year millions of Americans come down with a case, frequently as a complication of another illness, and about 60,000 die from pneumonia.