JONATHAN M. METSCH, Dr.P.H. – Tracking Emerging Public Health Challenges –June 19, 2026 – Measles
“The US has recorded more than 2,000 confirmed measles cases so far this year – near the total of 2,228 recorded in all of 2025, and on track to become the worst year for measles in decades as states struggle with the loss of federal funding for public health.
The virus continues to spread in unvaccinated and under-vaccinated communities, including among babies too young to be vaccinated, and it reveals the depths of the twin crises of misinformation and public health in the US.
The US recorded 2,030 cases on 4 June, though experts believe the true number is about three times higher. Cases in Utah appear to be winding down, while cases in Virginia and Pennsylvania appear to be picking up.
“I think it’s going to be a busy summer,” said Andrew Pavia, a George and Esther Gross presidential professor at the University of Utah who spoke in his personal capacity as an infectious disease expert.
Utah has shown a new side of the outbreak. “What makes Utah different than South Carolina and Texas is that it spread throughout the entire state and became much more widely distributed,” Pavia said.
Even so, there were two factors that made a difference in whether cases were contained, Pavia noted: “It hit hardest in communities that had relatively low vaccination rates and relatively limited public health departments.”
While the Utah cluster began in a community with low connections to public health, making it hard to track cases, it quickly spread elsewhere. “With immunization rates having fallen off for 15 to 20 years in some places, there are young adults who are susceptible, who grew up in otherwise typical middle-class settings,” Pavia said.
Controlling measles also requires strong public health: vigorous contact tracing, isolation for the sick, and quarantine for the exposed – an increasingly politicized task following the Covid pandemic. Utah has a decentralized public health system, so most of the response came from local public health departments.
“Some of these small health departments are very stressed for personnel, funds and training, particularly after the massive cuts that the administration made to pass through money that went to state and local health departments – I think it was $11bn they took away,” Pavia said.” (1)
“A highly effective vaccine has long kept measles at bay in many parts of the world. But as childhood vaccination rates drop, leaving a growing population vulnerable to the extremely contagious virus, one question takes on new urgency: What’s the backup plan?
There are currently no antiviral treatments against measles. Though physicians can offer ways to manage symptoms, which often include fever, fatigue, cough and a hallmark blotchy rash that spreads from head to feet, they can’t fight off the virus itself.
“We haven’t had the need to develop measles antivirals,” said Ruth Lynfield, an epidemiologist at the Minnesota Department of Health in St. Paul, in a May 27 news briefing. “It hasn’t been a priority. I do think we need to invest in that now.”
The lack of measles-specific treatments is in part due to the vaccine’s success. With two doses, the shot prevents about 97 percent of measles cases. Vaccination rates above 95 percent across a population create a blockade of protection that the virus has a tough time breaking through. That blockade protects people who can’t get the shot, including babies younger than a year old and people with compromised immune systems.
But vaccination rates are slipping around the globe, including in the United States and Canada, as well as some European countries. The backslide can be attributed in part to concerns about vaccine safety that are not supported by scientific evidence, as well as distrust of medical professionals and lack of access. Funding cuts for global aid could also lead to lower vaccination rates in regions where measles still circulates broadly, which could drive future outbreaks.
As a result, measles cases in the United States are on the rise. This year, cases are poised to surpass last year’s count — the highest since 1991. Of the 2,073 cases reported as of June 11, more than 90 percent have been in unvaccinated people or in people whose vaccination status is unknown. Based on the deluge, which began in January 2025, the country is at risk of losing its measles elimination status.”
“One of the biggest misunderstandings about measles is that it’s “not that bad,” says Kathryn Hastie, a structural virologist at the La Jolla Institute for Immunology in San Diego. But the virus can cause a range of complications that can severely impact people’s lives, including pneumonia and blindness. The virus can erase immune memory, leaving people vulnerable to other infections. What’s more, about 1 out of every 1,000 people infected with measles develop encephalitis, which can result in permanent brain damage. And 1 to 3 children, a group at high risk of measles, die of the disease for every 1,000 that are infected.” (2)
“Saravir, one of the biotech companies developing a measles antibody treatment, now sees “a potential multi-billion dollar market opportunity.” Dr. Ronald Moss, the company’s chief executive, cited figures showing that in the United States and the European Union — where measles has also resurged — there are more than 7 million babies, 26 million people with compromised immune systems and 11 million pregnant women, all of whom are uniquely vulnerable to measles.
Even if a small percentage of that market ends up becoming exposed to the virus, he said, “that’s a pretty big population that we would want to protect.”
If the drug makes it through trials, he expects the infusions to cost roughly $2,500. (Antibody treatments are generally more expensive than antiviral pills.)
Other companies, less certain of the potential return on investment, have decided to pursue paths traditionally used for rare disease treatments, such as asking the Food and Drug Administration for orphan drug status. This offers financial incentives to develop drugs for conditions that affect fewer than 200,000 people nationwide.” (3)
“The Texas and Utah cases now sit at the center of an unusually technical — and politically fraught — question: whether the United States will lose its measles-free distinction.
Countries aren’t penalized for losing the status, but it’s an indication of cracks in a nation’s once rock-solid immunization programs, a loss of faith in vaccines among its people — or both.
To have any chance of keeping the designation, the U.S. will need to make a strong case that measles didn’t spread endemically — from person to person in a continuous chain within the country for more than a year. If the Texas virus, for example, made its way across the Southwest to Utah and continued infecting people there, that would be a problem. But if cases in Utah were instead sparked by a patient who caught measles abroad, that would be a new chain, restarting the clock.
For clues, the Centers for Disease Control and Prevention is analyzing the full genetic code of measles viruses that infected patients. Last November, the CDC’s leader at the time said preliminary genomic analysis suggested the Utah cases were not directly linked to those in Texas. A spokesperson for the Department of Health and Human Services told ProPublica that the work was done by the state laboratories and the CDC is conducting a more comprehensive investigation.
ProPublica embarked on its own analysis, reviewing over 1,800 whole genome sequences, including those released as recently as last month, to compare the genetic fingerprints of measles viruses circulating in the U.S. and Canada. This showed that the measles virus still spreading in Utah as of this May is very closely related to the one that sickened Texans over a year ago.
ProPublica’s analysis isn’t a smoking gun that proves endemic spread. It’s impossible to tell from this information whether the virus spread from state to state or if it at some point left the country and was brought back by a sick traveler.
But given how similar the viruses are in the sequences ProPublica identified, it’s going to be difficult for the U.S. to prove measles isn’t endemic — “unless CDC has something up their sleeves,” said Dr. Alberto Severini, a retired molecular virologist and measles expert who spent two decades at Canada’s Public Health Agency.” (4)
Guatemala measles outbreak tops 7,000 confirmed cases, https://outbreaknewstoday.substack.com/p/guatemala-measles-outbreak-tops-7000
1.Outbreak driven by falling vaccination and misinformation as federal public health cuts hamper state response, by Melody Schreiber, https://www.theguardian.com/us-news/2026/jun/10/measles-us-spike
2.Measles has no treatments. Changing that may not be easy, By Erin Garcia de Jesús, https://www.sciencenews.org/article/measles-treatments-vaccine-clinical-trial
3.The New Race to Find Treatments for Measles, By Teddy Rosenbluth, https://www.nytimes.com/2026/06/11/well/measles-treatments-drug-vaccine.html
4.What ProPublica Found in the Genetic Code of America’s Measles Outbreaks, by Nat Lash and Patricia Callahan, https://projects.propublica.org/measles-outbreak-analysis-utah-texas/
curated by Jonathan M. Metsch, Dr.P.H.
Clinical Professor of Environmental Medicine, Icahn School of Medicine at Mount Sinai