Millions of kids each year get immunized to protect against disease. Diseases like Smallpox and Polio now affect far fewer people because of widespread vaccination.
Vaccines contain inactive viruses or bacteria that stimulate your body's B and T immune cells to produce antibodies, which then fight the disease. When enough people get immunized, vaccines produce "herd immunity": when someone is sick, the disease is contained by those who've had the vaccine, preventing it from spreading further and getting to those who are most vulnerable. But if only a few people are vaccinated, the disease spreads easily through the population and outbreaks can occur.
In 1998, a paper in a major medical journal proposed a link between autism and the vaccination for measles, mumps, and rubella. The popular press (and some celebrities) fueled anxiety about vaccinations based on this report. Some vaccinations can have side effects, like soreness and fever. But autism is a complex neurobehavioral disorder that occurs with a spectrum of symptoms. A rise in prevalence may have more to do with changing diagnostic standards than other factors. In fact, over a dozen studies have failed to find any connection between autism and vaccines and that original paper was retracted amid allegations of fraud and conflicts of interest.
Yet the actions of celebrities and the media can have a lasting effect: more than half of Americans still suspect there's a link between vaccines and autism. Call it a case of "herd mentality."
The consequences can be serious: in Ireland, vaccinations dropped about 30%, resulting in 1500 new cases of Measles and Mumps, including 3 deaths. And in the U.S., states with lowered vaccination rates are currently experiencing outbreaks of measles and epidemic levels of whooping cough. So don't be immune to good advice: better a sore bottom, than a deadly bottom line.There may be small errors in this transcript.