Measle outbreak from Disneyland
Liz Levey, ‘Doah Staff Writer
February 4, 2015
A measles outbreak spreading across the country has sickened 86 people in 14 states, raising fears of an epidemic. But what’s different this time is the high number of adults falling ill – including some who have been vaccinated.
The outbreak originated in Disneyland in December, sickening 11 people last month and another 56 people in January. The others most likely contracted the disease while traveling internationally. The median age of infected patients is over 20, and not all of those were part of the anti-vaccination movement, whose adherents deliberately forego vaccines out of fear that they will cause more harm than good. At least six people diagnosed with measles got their measles-mumps-rubella vaccine, and all but two of them got the standard two-shot sequence.
This isn’t about measles vaccine effectiveness, which is one of the most effective in the world. Two doses provide 97 percent protection against infection and has been proven safe. This is about the effect an outbreak has on the wider population when select groups of people remain unvaccinated. The vast majority of both adults and children infected were unvaccinated – whether for health-related issues, lack of awareness or as part of the anti-vaccination movement. Medical professionals say the ongoing measles outbreak is the inevitable consequence.
Measles is a wildly contagious disease and is still common globally, sickening nearly 20 million people annually. The virus spreads through the air when an infected person breathes, sneezes or coughs. It’s so contagious that if one infected person coughs in a crowded area, 90 percent of the non-immune people in the vicinity will catch it.
Even with the safest and most effective vaccines, there’s still a “long tail,” meaning that a certain number of people won’t build up the needed antibodies to protect them from the measles. If the vaccination rates were high enough to prevent an outbreak, those with waning immune systems wouldn’t be at much of a risk. It’s what experts refer to as the “herd immunity.” But the moment vaccination rate falls below 90 or 95 percent, the disease can find enough hosts to spread. When you have only an extremely small proportion of the population vulnerable, herd immunity will protect them. When you have a substantial proportion, like the 10 percent-plus seen in certain communities in California, then herd immunity doesn’t work very well.
This appears to be what happened at Disneyland, where measles took hold in even vaccinated adults. While vaccinations may not fully protect everyone because of a mixed antibody response, it still contributes to increased overall public immunity and prevents these outbreaks before they even start.
Symptoms of measles include fever as high as 105, cough, runny nose, redness of eyes and a rash that begins at the head and spreads to the rest of the body. It can lead to inflammation of the brain, pneumonia and death. Health officials said infants too young to be immunized are particularly at risk and should avoid large crowds where international travelers are concentrated, such as theme parks and airports. The measles virus can linger in the air for up to two hours, and babies under a year old are especially at risk because they’re too young to receive the vaccine.
The U.S. has been measles-free for 15 years but this outbreak is being blamed on parents who have chosen not to give their children the MMR vaccine, due to concerns about potential side effects. No authoritative research has been published to back up claims that the vaccine may be linked to autism and bowel disease
Autism and vaccines: It’s the link that just won’t die. The American Academy of Pediatrics, the CDC, the World Health Organization and the Institute of Medicine all agree that there’s probably no relationship between autism and vaccines. But if the case is that solid, why do so many people remain unconvinced, from actress Jenny McCarthy, who went on “Oprah” to say she believes that a vaccination caused her son’s autism and wrote a book about it to Sen. John McCain, who said he thought there was “pretty strong evidence” that some vaccines cause autism.
Their beliefs may have been validated when federal officials said that a Georgia girl was entitled to compensation because vaccines may have aggravated an underlying condition, causing autism-like symptoms. Researchers at the National Institute of Mental Health (NIMH) said that they are still taking a careful look into parent concerns that vaccines are tied to the disorder. “I think there’s a lot of emotion around the issue of autism now. It engenders a lot of fear in parents and clinicians alike,” Lee Sanders, MD, MPH, associate professor of pediatrics at the University of Miami Miller School of Medicine, told WebMD.
The concern is difficult to suppress for a number of reasons. Parents are bombarded with information that can take a life of its own online. The concepts around scientific testing are difficult to understand, making it tough to separate good science from bad. Until scientists can prove exactly what causes autism, it’s difficult to definitively disprove anything. When something bad happens to a child, people demand to know what or whom is to blame. “Parents are clamoring for a cause,” says David Tayloe, MD, a pediatrician in Greensboro, N.C. and president-elect of the American Academy of Pediatrics. “It upsets families, and it upsets me But all the fear and anger about vaccines is misplaced,” he says. “There’s just nothing there.”
While public health officials try to stop the spread of measles, Phoenix prepared for the mass amounts of people that were attending Feb. 1, 2015 Super Bowl. Three clinics have experienced a surge in visitors requesting measles vaccinations for their children, according to health officials, who reported a 50 percent rise in vaccination requests over last year. Time will tell if this surge will start a new found confidence in vaccinations and what actions will be taken if you haven’t been vaccinated.