Measles Resurgence 2026: Experts Explain the Crisis

The United States is experiencing its worst measles resurgence in decades, with more than 5,000 cases reported in 2026 and growing concerns about vaccine confidence, public health preparedness, and the protection of vulnerable populations. The resurgence also raises important questions for people living with autoimmune disease, particularly those receiving treatments that suppress their immune systems.

On November 6, 2026, the Brown University Pandemic Center hosted a webinar, “Measles: Why It’s Not Stopping,” featuring Paul Offit, MD, of Children’s Hospital of Philadelphia, and Jonathan Temte, MD, PhD, of the University of Wisconsin School of Medicine and Public Health. Moderated by Jennifer Nuzzo, DrPH, director of the Pandemic Center, the discussion explored why measles is returning after its elimination in the United States in 2000, the consequences of declining vaccination rates, and what it will take to stop the outbreaks.

Why Is Measles Resurging in the United States?

Offit explained that the success of measles vaccination may have contributed to people forgetting how dangerous the disease can be, leaving misinformation about vaccine safety to fill that gap. Because measles is extraordinarily contagious, even relatively small pockets of unvaccinated people can experience substantial outbreaks. The panelists also emphasized that the resurgence is not being driven by measles mutations that evade vaccine protection. The existing vaccine remains highly effective, but declining and uneven vaccination coverage creates opportunities for transmission.

Temte described outbreaks concentrated in rural communities with historically low vaccination coverage, emphasizing that being unvaccinated does not necessarily mean someone opposes vaccines. Some communities have longstanding patterns of low immunization or limited engagement with preventive healthcare. The panelists stressed the importance of trusted community relationships, better access, and proactive outreach rather than waiting until outbreaks occur.

The resurgence is also affecting adults who were never vaccinated or infected during childhood. Offit described increasing cases among adults in Pennsylvania, including pregnant women exposed to measles, and warned about the return of congenital measles infections. These developments underscore that measles is not solely a childhood disease and can have particularly serious consequences for vulnerable populations.

As the United States faces the possibility of losing its measles elimination status, Nuzzo raised concerns about what the resurgence signals for the nation’s ability to respond to other infectious disease threats:

Why Community Immunity Matters

High vaccination coverage helps protect people who cannot safely receive certain vaccines or whose immune systems may not respond adequately to vaccination. This is especially important for some people living with autoimmune disease who receive immunosuppressive treatments. Because MMR is a live vaccine, it may be contraindicated for individuals with severe immunosuppression, depending on their treatment and medical circumstances.

For those at high risk of severe measles, exposure may require urgent medical evaluation and preventive treatment with immune globulin, which can provide temporary protection when administered promptly. These considerations illustrate why preventing measles transmission throughout the community remains so important.

Measles, Immune Amnesia, and Autoimmune Disease

Beyond its immediate symptoms, measles can have lasting effects on immune function through a phenomenon known as immune amnesia. Offit explained how this loss of previously acquired immune protection can increase susceptibility to other infections for years after recovery.

The panel also discussed serious complications, including pneumonia, encephalitis, and subacute sclerosing panencephalitis (SSPE), a rare, fatal neurological condition that can emerge years later.

Near the webinar’s conclusion, the panel addressed claims that contracting measles could prevent cancer, heart disease, or autoimmune disease. Offit attributed these claims to Health and Human Services Secretary Robert F. Kennedy Jr. and directly rejected them, emphasizing that there is no established scientific evidence supporting such protection.

Offit challenged the idea that immunity acquired through infection is inherently preferable to vaccination, suggesting that “natural immunity” would be better described as “survivor-induced immunity.” He recalled that both he and his children developed immunity to measles, but through very different experiences: he contracted the disease as a child, while his children received the vaccine.

How Safe Is the MMR Vaccine?

The discussion also offered a compelling example of the rigorous scientific review behind vaccine safety recommendations. Temte recalled chairing a working group evaluating the MMRV vaccine, which combines protection against measles, mumps, rubella, and varicella (chickenpox) into a single injection, rather than administering the three-disease MMR vaccine and chickenpox vaccine separately.

Although the four-disease vaccine was effective, safety monitoring identified a slightly increased risk of febrile seizures (seizures triggered by fever) following the first dose in young children. Temte explained that febrile seizures are generally brief and do not result in lasting neurological harm. Nevertheless, his working group spent an entire year investigating the finding, reviewing evidence, and debating the appropriate recommendations.

The resulting guidance favors separate MMR and varicella vaccines for the first dose in children ages 12–47 months, while generally preferring the combined MMRV vaccine for the second dose. Temte’s account demonstrated how even relatively uncommon adverse events receive careful scrutiny, with recommendations adjusted when scientific evidence warrants it.

How Can the U.S. Stop Measles Outbreaks?

The discussion also raised a difficult question: Can public confidence in vaccination be restored before more people experience the consequences of preventable outbreaks? Offit recalled asking Maurice Hilleman, who developed the measles vaccine, whether education about the vaccine’s safety and effectiveness, along with the dangers of measles, would be enough to maintain vaccination rates. According to Offit, Hilleman paused for a long time before responding, with a tear in his eye, that he believed the virus itself would ultimately have to educate the public.

Nuzzo offered a more hopeful perspective, arguing that communities should not have to experience preventable illness and death before taking action. She emphasized that many people in under-vaccinated communities are not necessarily opposed to vaccination and that public health agencies have opportunities to build trust, improve access, and engage with community leaders before outbreaks occur.

The measles resurgence has exposed vulnerabilities extending beyond declining vaccination coverage, including gaps in disease surveillance, community outreach, and public trust. As the panelists emphasized, preventing future outbreaks will require sustained engagement and stronger public health systems, particularly to protect people who cannot be vaccinated or whose immune systems may not provide adequate protection.

Reference

Nuzzo, J. (Moderator), Offit, P., & Temte, J. (Presenters). (2026, November 6). Measles: Why it’s not stopping [Webinar]. Pandemic Center, Brown University.