The flu can definitely set you up for bacterial pneumonias.

Flu vaccine is far and away the most underutilized.

If you've had a cough that lasted weeks, a cough that just doesn't seem to go away, chances are it was pertussis.

Your child can die from chickenpox.

What really reinvigorated vaccines was Prevnar, the pneumococcal vaccine that prevents against meningitis and ear infections. Here was the first vaccine to cross the billion-dollar mark.

Physicians who care for adults generally don't think about vaccines as much as pediatricians do, and adults think of vaccines as a kid thing.

When you're in the womb, you're in a sterile environment. When you enter the birth canal and the world, you're not. Very quickly, you have, living on the surface of your body, trillions of bacteria, literally trillion.