Vaccines have dramatically transformed the landscape of medicine over the course of the 20th century. Before vaccines, parents in the United States could expect that every year:
- Polio would paralyze 10,000 children.
- Rubella (German measles) would cause birth defects and mental retardation 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.
However, the disappearance of many childhood diseases has led some parents to question whether vaccines are still necessary. Further, a growing number of parents are concerned that vaccines may actually cause other diseases. Although unfounded, these concerns have caused some parents to delay vaccines or withhold them altogether from their children.