Measles is back, fueled by lack of vaccination and misinformation

In 2000, the United States achieved a major public health milestone: Measles was declared eliminated. Thanks to widespread uptake of the measles, mumps, and rubella (MMR) vaccine, cases of this highly contagious virus no longer originated here. But in 2025, that victory is hanging by a thread. Measles has returned, and it poses a nightmare for all of us.

As of March 27, the CDC reported 483 total confirmed measles cases across 20 states. This is more cases in the first few months of this year than were seen in all of 2023. With 93% of cases linked to outbreaks, and nearly all occurring in unvaccinated individuals, it is clear we are not dealing with random chance — we are witnessing the consequences of unfounded fears of vaccines resulting in declining vaccination coverage.

It is tempting, as new Health and Human Services Secretary Robert F. Kennedy Jr. has been doing, to downplay measles. After all, most people survive. But measuring the impact of measles by deaths alone misses the picture. This disease causes hospitalizations, drains public health resources, compromises immunity over one’s life, overwhelms intensive care units, and exacts a steep financial toll. To ignore these effects is to grossly underestimate the harm of measles.

Start with hospitalizations. In 2025, 17% of people infected with measles have been hospitalized. Among children under five, that number jumps to 27%. And the hospitalizations are not just overnight stays. Complications like pneumonia, encephalitis, and severe dehydration can require intensive care. An outbreak in 2018—2019 in New York City saw 7.6% of patients hospitalized, and nearly 41% of those required intensive care. These are not mild colds; they are devastating, life-altering illnesses, particularly for children.

The economic burden is staggering. Take, for example, the same New York City outbreak that cost $8.4 million, or the 2019 outbreak in Clark County, Washington that cost $3.4 million, largely due to the necessary public health response and lost productivity. These figures do not even account for the indirect costs: missed workdays, school closures, restricted travel. Every outbreak requires rapid mobilization of contact tracing, public awareness campaigns, emergency vaccination drives, and isolation efforts. There is also the hidden cost of "immune amnesia." Measles does not merely cause acute illness; it can also weaken the immune system for months or even years. By attacking memory immune cells, the virus reduces the body’s ability to fight off infections against which it had previously been protected. In essence, measles can wipe clean the immune system’s hard drive, leaving people more vulnerable to everything from the flu to COVID-19 to bacterial infections.

Of course, the risk of death matters. In the U.S. this year, there has already been one confirmed measles-related death, and another likely. Globally, measles caused over 100,000 deaths in 2023. The U.S. is not immune to a measles pandemic — especially since infected individuals can easily travel, and outbreaks can explode given how infectious the measles virus is.

So, what went wrong? One key factor is the decline in MMR vaccination coverage, worsened by the COVID-19 pandemic. Among U.S. kindergartners, coverage has dipped below the critical 95% group threshold, with some communities falling much lower. This is not just a number; it is the tipping point. Once immunity in a community drops, measles can spread like wildfire.

What can be done? First, we must boost vaccination rates. Vaccines must be easy to access, misinformation corrected, and communities engaged locally. Health care providers and government agencies must be empowered to use evidence-based communication that addresses vaccine hesitancy head-on. Second, we need the capacity to engage in a rapid outbreak response. Mass vaccination campaigns, targeted community engagement, and robust contact tracing are essential. When used quickly and decisively, these strategies can quash outbreaks before they spread. Third, we need to maintain strong surveillance infrastructure and enact policies that limit nonmedical exemptions to vaccination. Above all, we need political leaders to stop spreading nonsense and implement science-based policies that maintain high vaccination coverage and prevent outbreaks. Anti-vaccine legislation, unfounded ‘cures’ for measles, and vaccine hesitancy are detrimental roadblocks to measles elimination.

The resurgence of measles is a flashing red warning light. It tells us that our vaccination infrastructure is weakening, that misinformation has and is gaining ground, and that we have let our guard down. But its reappearance still offers a chance to course-correct before it is too late.

We must stop pretending that measles is only dangerous when it kills. Let’s recognize the broader harm it causes to health, to families, to communities, and to our already overburdened health system. Measles is a very serious disease. We need to respond to that fact.

This guest essay reflects the views of Arthur Caplan, head of the Division of Medical Ethics at NYU Grossman School of Medicine, and Felicia Pasadyn, an NYU Grossman School of Medicine medical student.