Measles More Deadly Than We Thought

MP3 WAV

More Information

Deadly Measles Complication More Common Than Doctors Thought
A deadly complication of the measles, which can occur years after a person is infected with the virus, is more common than researchers previously thought, according to a new study.

Measles History
The first written account of measles dates back to the 9th century. Find out more about measles at this CDC site.

What is Herd Immunity?
The term "herd immunity" refers to a means of protecting a whole community from disease by immunizing a critical mass of its populace. Vaccination protects more than just the vaccinated person. By breaking the chain of an infection's transmission, vaccination can also protect people who haven't been immunized. But to work, this protection requires that a certain percentage of people in a community be vaccinated. What factors determine where that critical-mass threshold lies? And once it's in place, how does herd immunity cocoon the most vulnerable among us?