Vaccines have dramatically transformed the landscape of medicine over the course of the 20th century. However, the disappearance of many childhood diseases has led some to question whether vaccines are still necessary. Further, concerns that vaccines may actually cause other diseases have caused some to delay or refuse vaccines altogether. Find out more about not only vaccines but also the diseases they prevent. 

On this page find a list of vaccines and diseases to get more specific information about each and learn what life was like before vaccines.

Life before vaccines

Before vaccines, every year in the United States:

• Polio would paralyze 10,000 children.
• Rubella (German measles) would cause birth defects and mental delays in as many as 20,000 newborns.
• Measles would infect about 4 million children, killing about 500.
• Diphtheria would be one of the most common causes of death in school-aged children.
• A bacterium called Haemophilus influenzae type b (Hib) would cause meningitis in 15,000 children, leaving many with permanent brain damage.
• Pertussis (whooping cough) would kill 8,000 infants.

Vaccines have reduced and, in some cases, eliminated many diseases that killed or severely disabled people just a few generations before. For most Americans today, vaccines are a routine part of healthcare.

Reviewed by Paul A. Offit, MD, on July 18, 2022