The anti-vaxxers’ impact

After being officially eliminated in the U.S. in 2000, measles is making a comeback. Officials blame low vaccination rates. Here’s everything you need to know:

Who has been affected?
This year there have been six confirmed measles outbreaks in 10 states, including New York, Texas, and Washington state. At least 159 people have been infected, mostly young children. All of the outbreaks have occurred in communities with low vaccination rates. Washington is one of 17 states that allows vaccine exemptions for personal philosophical reasons, and nearly one out of four kindergartners weren’t vaccinated in Clark County, the epicenter of a measles outbreak that has prompted Washington’s governor to declare a state of emergency. About 90 to 95 percent of a population needs to be vaccinated against measles in order to keep the disease from spreading. “Measles is exquisitely contagious,” says Dr. Alan Melnick, Clark County’s public health director. “If you have a population that is unvaccinated, it’s like throwing a match into a can of gasoline.”

Why are high vaccination rates important?
Vaccines create “herd immunity.” If enough people have their shots, diseases can’t spread as easily, and that protects people who can’t be vaccinated themselves — including very young babies, people with vaccine allergies, and those with compromised immune systems. Herd immunity is especially important for measles, which is spread through the air by droplets from an infected person’s nose or mouth. One person can infect 12 to 18 other people in an unvaccinated population, making it one of the most contagious diseases known to science. While the most common symptoms include a high fever, runny nose, and a painful, spotty rash, many patients suffer serious complications. One in 10 children with measles suffers ear infections, while one in 20 develops pneumonia. Encephalitis, swelling of the brain that can cause permanent damage, …read more

Source:: The Week – Science