U.K. Measles Threat Menaces U.S.
Key to Protection: Keeping U.S. MMR Vaccination Rate High
Could It Happen Here? continued...
Even the 90% coverage threshold is not ideal.
"With measles it would be nice to get above 95%, but if we are above 90% everywhere -- that's our goal by 2010 -- we'd feel pretty good about that," Cochi says. "Every percentage point reduces the chance that a case of measles will cause a disease cluster. With more importations from the U.K., there will be more small outbreaks. But unless coverage drops substantially we won't have a major epidemic."
Unless, of course, Americans lose faith in MMR safety.
"With this misinformation out there, there is always the chance we might see that happen," Cochi worries. "Right now we have high coverage, so we won't see any kind of epidemic unless our national vaccination rates drop."
Measles Kills and Blinds
Measles is only one part of the MMR vaccine. Mumps and rubella are also serious illnesses. But measles is a lot scarier.
Measles is one of the most contagious diseases in the world. It's spread by airborne droplets that can linger in the air for hours. A very small dose of measles virus is all it takes for an unprotected person to get ill.
Before the vaccine became available in 1963, everybody got measles. There were as many as 4 million cases per year in the U.S., with 500 deaths. Even a healthy person gets seriously ill. But when a person is poorly nourished, measles can be a disaster. Among the poorer nations of the world, measles is still a major plague.
"Worldwide measles deaths in 1999 were 875,000 people," Cochi says. "Almost a million children died of measles at the end of the last century. Last year we think the deaths were down to about 700,000."
The decline in deaths is due to a major vaccination effort by the World Health Organization, the CDC, and other health organizations and charities. Worldwide vaccine coverage now is about 70%. In sub-Saharan Africa, it's just over 50% -- and rising, thanks to the huge international effort.
Still, the battle is far from over. In some nations, one in four children under 5 dies of measles complications. Measles is the leading cause of blindness in African children.