Progress in fighting measles in Europe has taken a substantial step back. This week, the World Health Organization stripped the UK of its measles-free status, just two years after it commended the country for eradicating the virus locally. The UK’s fate could very well be a harbinger of what will happen to the United States amidst an infuriating anti-vaccination movement.
Measles is a highly contagious disease, but it can only spread between people (as opposed to hiding in other animals). So if you can cut the chain of transmission in a particular area, mainly through high vaccination rates, you can fully prevent the virus from showing up—do that everywhere, and you can wipe it off the face of the Earth, like we’ve done with smallpox.
In 2017, WHO decided that the UK had eliminated the virus from within its borders, based on the low number of cases reported from 2014 to 2016 and an overall high vaccination rate. These infrequent cases were deemed to be brought over by people traveling from other countries where measles is still endemic. Even if these cases infected local residents, herd immunity would presumably prevent outbreaks from growing out of control.
But 2018 saw a dramatically higher number of confirmed measles cases—from 284 cases in England and Wales the year before to 991 cases, according to the UK government. And in the first quarter of 2019 alone, there were over 200 confirmed cases. What’s more, the same strain of measles was routinely detected in cases throughout 2017 and 2018, indicating the virus had managed to stay alive in the country.
These developments, the UK government reported Monday, led WHO to revoke the country’s measles-free status.
The UK’s stumble reflects a sharp, recent decline in controlling the spread of measles in Europe and elsewhere. In January 2017, for instance, there were fewer than 2,000 confirmed or suspected cases documented across the WHO’s European region, which encompasses 57 countries. But by January 2019, that number had climbed to nearly 20,000.
The U.S. hasn’t fared quite as badly by comparison, though the situation is quickly sliding into trouble. There were over 350 cases in 2018, more than double the amount in 2017. And as of August 15, there have been more than 1,200 cases reported across 30 states this year. The number is the highest seen since measles was declared eradicated in the U.S. in 2000, and it’s the highest total since 1992.
Though no deaths have been reported as a result of measles, over 100 people have been hospitalized, many with serious complications like pneumonia or brain swelling.
Things could get worse still. There are six ongoing outbreaks in four states—New York, California, Washington, and Texas—as well as 21 new cases reported just last week. So it’s not out of the realm of possibility that measles could reestablish a foothold in the U.S., as the CDC has warned.
The majority of cases behind this global resurgence have happened among the unvaccinated. Overall childhood vaccination rates have remained high in the UK and U.S., but there are many communities in these countries where rates have dipped below the level needed to provide herd immunity. In many of these communities, anti-vaccination propaganda has spread far and wide.
The measles vaccine also comes in two doses, and people who only get the first are at higher risk of catching the disease. In the UK, rates of people getting the second dose are lower than they should be. According to the UK government, only 87.4 percent of eligible children have gotten the second dose—lower than the 95 percent threshold recommended by WHO.