This is how worried you should be about the measles outbreak

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More than half a century ago, hundreds of Americans died every year from measles, one of the most contagious diseases known to man. But fears had subsided by 2000, when a vaccine almost completely eliminated the disease in the states.

Now, measles has come roaring back, with current outbreaks in 15 U.S. states and 97 other countries. One county in upstate New York tried to ban unvaccinated minors from public places. Washington State declared a state of emergency after a measles outbreak sickened 73 people in just one county. And on Tuesday, New York City declared a public health emergency and mandated that residents in certain Brooklyn communities get vaccinated or face a $1,000 fine.

But experts also say people shouldn’t be worried about the outbreaks — as long as they’re inoculated. Two doses of the measles, mumps, rubella vaccine (MMMR) can leave a person nearly 97-percent immune from the illness for life — even in areas where public vaccination rates fall below the recommended levels to achieve what’s known as “herd immunity.”

And if someone isn’t immune, public health experts recommend they don’t travel to areas experiencing outbreaks — and to get vaccinated as soon as they can.

Reports of measles cases went up in 2017 by 41,000 cases from the year before, largely because of gaps in vaccine coverage, according to the World Health Organization (WHO). In Western countries, those holes often stem from misinformation that’s convinced some parents vaccines cause autism or developmental delays — despite heaps of evidence to the contrary.

This year, WHO listed “vaccine hesitancy”, or people who don’t want to get the available vaccines for preventable diseases, among its top 10 threats to global health and specifically cited the global measles outbreak.

“I didn’t think we would be in this place in 2019, to be honest,” said Robin Nandy, principal adviser and chief of immunization at UNICEF. “Things were going really well until about 10 years ago, and then the immunization coverage started to stagnate.”

Like the flu, the measles virus spreads easily by coughing or sneezing. But what makes the disease more contagious are its minuscule particles that “kind of float in the air” for up to two hours, according to Yvonne Maldonado, chief of Pediatric Infectious Diseases at Stanford University. That ultimately means a person can walk into a room where a sick person had been hours before and still get sick. People can also spread the illness days before they’re symptomatic.

Once one unvaccinated person has measles, 90 percent of those close to them who aren’t immune will also become infected, according to the CDC.

“It’s like the Febreeze of diseases,” said Marie Wilson, a nurse and spokesperson for the Association for Professionals in Infection Control and Epidemiology. “It stays suspended in the air for a long period of time.”

Symptoms of the illness can include fever, coughing and sore throat, runny nose, and a skin rash. And once someone is sick with measles, no specific treatment exists to ensure a quick and safe recovery. The disease is most dangerous to babies too young for the vaccine and people with compromised immune systems, like cancer patients or the elderly. Most measles-related deaths result from complications associated with the illness, like encephalitis, a condition that can cause fatal brain-swelling.

Measles outbreaks related to unvaccinated travelers have surfaced in New York, Washington, California, Illinois, and Texas. Some state and city health departments have even started issuing exposure warnings at airports for specific dates and terminals.

“If they’ve received full vaccination, I’m not sure there’s cause for worry,”, Jennifer Nuzzo, a senior scholar at the Johns Hopkins Center for Health Security said of people hoping to travel. “It may be worth talking to a clinician. Some people think they’ve been vaccinated and they haven't.”

Concerned people can receive a blood test from their doctor to confirm their immunity.

Just in the U.S., the CDC has confirmed 465 measles cases so far this year, although no one has died from the disease since 2015. Three places — Clark County, Washington; Rockland County, New York; and Brooklyn, New York — have experienced the majority of cases. Those counties have two contributing factors in common: insular communities that travel internationally and lower-than-usual vaccination rates.

But the numbers in the U.S. pale in comparison to nations like the Philippines — which has seen 12,736 measles cases this year and 203 deaths — and Ukraine — which has had more than 15,000 cases since the end of December. Ukraine also has some of the lowest childhood vaccination rates in the world.

Very sick people or infants, the most at-risk groups, are unlikely to get sick from a preventable disease if at least 95 percent of their community is vaccinated. That’s why public health officials and doctors have used the recent outbreaks as a reason to remind their patients of herd immunity.

“Controlling an outbreak of measles is exponentially harder as the outbreak grows bigger,” said Nancy Messonnier, director of U.S. Centers for Disease Control’s (CDC) National Center for Immunizations and Respiratory Diseases. “Individuals who are unvaccinated put themselves, their families, and communities at risk.”

But some people can’t get the vaccine — which contains a weakened form of the virus — if their immune system is compromised, or if they’re very young. In the U.S. 47 states offer religious exemptions and 17 offer moral or personal exemptions, according to the National Conference of State Legislatures.

Once a community dips below the threshold, however, outbreaks become likely. Still, it’s very unlikely for a vaccinated person to become ill even if they’re in a community that’s undervaccinated. The percentage of young children who haven’t gotten any vaccinations has quadrupled since the U.S. declared measles eliminated in 2000, although vaccine coverage still remains high overall.

“People haven’t seen kids dying of measles in a very, very long time and that creates a sort of complacency,” Nandy said. “I hope these outbreaks can serve as a warning sign that we’re not out of the woods."

Cover image: This undated image made available by the Centers for Disease Control and Prevention on Feb. 4, 2015 shows an electron microscope image of a measles virus particle, center. (AP Photo/Centers for Disease Control and Prevention, Cynthia Goldsmith)