The United Kingdom is facing a measles outbreak, while cases have also popped up in a few U.S. states in recent weeks, leading to health authorities on both sides of the pond to issue urgent warnings.
The virus, which was declared eliminated in the U.S. in 2000, is a wake-up call for the importance of vaccination to personal and public health. The U.K. only recently reachieved measles elimination status in 2021 after having lost the distinction in 2018.
Unlike COVID-19 vaccines, which help prevent serious illness but don't prevent infection, the measles vaccine is almost 100 percent effective in preventing infection. And almost everyone who has been recently infected in the U.K. and U.S. is not vaccinated against measles.
The Centers for Disease Control and Prevention (CDC) on Thursday advised health care providers to be alert for potential measles symptoms, which include a rash; cough; sore or swollen eyes; and flu-like symptoms. Providers should also be aware of patients who have recently traveled abroad.
“Measles cases often originate from unvaccinated or undervaccinated U.S. residents who travel internationally and then transmit the disease to people who are not vaccinated against measles,” the CDC’s alert stated.
“The increased number of measles importations seen in recent weeks is reflective of a rise in global measles cases and a growing global threat from the disease.”
In the U.K., more than 300 probable cases — 216 of which are confirmed — have been detected since October, with the majority centered around the city of Birmingham.
Since December, the CDC has received notice of at least 23 measles cases in the U.S., with seven having been imported by international travelers. States that have reported measles cases include Delaware, Georgia, New Jersey, Pennsylvania, Virginia, and Washington state.
Jenny Harries, chief executive of the U.K. Health Security Agency, recently warned the infections in her country would continue to spread without urgent action — and vaccinations.
“Immediate action is needed to boost MMR uptake across communities where vaccine uptake is low,” Harries said during a visit to Birmingham.
In the U.K. and the U.S., MMR (measles, mumps and rubella) vaccinations remain high but have fallen away from the ideal 95 percent rate, which is the target countries aim to reach by 2030, as well as the coverage the World Health Organization recommends to prevent measles outbreaks.
As KFF noted last summer, MMR vaccination rates in the U.S. have seen a slight decline in recent years, reaching 93 percent among kindergartners during the 2022-23 school year, the lowest this figure has been in almost a decade. The U.K. mirrored this trend, with MMR vaccination rates at the age of 5 falling to 92.5 percent, the lowest since 2010-11.
"We've started to lose our herd immunity," Keri Cohn, physician and partnership chair for the American Academy of Pediatrics, told The Hill.
"So, you really need to have 95 percent of the population vaccinated in order to have good herd immunity for measles. That number is less for other organisms, but because measles is so contagious, you really have to have such a high number," Cohn explained.
Like many health issues occurring in the world today, experts see a link between measles outbreaks and the COVID-19 pandemic.
“Generally, we certainly saw a real slide in the provision of essential health services like childhood vaccines during COVID. And that's continued,” said Elisha Dunn-Georgiou, president and CEO of the Global Health Council.
According to the CDC, more than 61 million measles vaccine doses were postponed or missed globally from 2020 to 2022, increasing the risk of outbreaks both in the U.S. and abroad. While measles is still considered endemic in countries like Yemen and India, Dunn-Georgiou said high-income like the U.S. and the U.K. shouldn’t be seeing outbreaks.
Vaccine hesitancy and disinformation are likely contributing factors to waning immunization rates, but Dunn-Georgiou also opined that recent measles outbreaks may be a sign the U.S. is falling victim to its success in combating the disease.
“I think there's another piece around infectious disease that is not so much hesitancy but complacency. Like if you don't see how terrible it is, you don't realize how terrible it is until it happens,” she said. “When diseases get completely under control, I think there's a little bit of amnesia.”
Measles cases could potentially snowball in the U.K. Andrew Pollard, chair of the British government’s Joint Committee on Vaccination and Immunization, recently told The Guardian there is “a very large susceptible population of children” in the country.
Despite the potential for spread, Dunn-Georgiou was doubtful that travel restrictions between the U.S. and the U.K. would be necessary.
“Travel bans have not proven to be that effective of a public health control,” Dunn-Georgiou said, noting the virus appears to so far be contained in one region of the U.K., the West Midlands.
“And measles is one of those diseases where if you are vaccinated, you won't get it,” she added. “It would necessitate ... a child under the age of seven getting on to a plane with measles and traveling to a community nobody's vaccinated.”
And measles always carries the risk of becoming a serious infection. Cohn noted children who get infected "are not infrequently needing hospitalization."
"About 25 [percent] to 30 percent of them end up having complications that can range from otitis media to pneumonia to even death," Cohn said, though she also noted that treating measles shouldn't be a challenge for most hospitals. The real challenge when it comes to measles is identifying and isolating cases before they can spread.
