Measles cases are rising, and RFK Jr. is only making it worse

The number of measles cases in the U.S. has soared over the past two years. In 2024, there were 285 reported cases, while in 2025, there were 2,280 cases. The number of cases reported by the Centers for Disease Control and Prevention as of Feb. 19 is 982 and growing. The U.S. is on track this year to have the most measles cases since 1990.

South Carolina, Utah and Florida are the states with the most cases so far this year. Illinois now has two cases, according to the Illinois Department of Public Health.

This surge in cases places the U.S. at risk of losing its measles elimination status, which it has held since 2000, largely driven by effective measles vaccination uptake.

Some may argue that measles is a harmless infectious disease, so children having measles is more of an inconvenience than a risk. This is simply not true.

Measles can cause an acute encephalitis, or swelling of the brain, as well as death.

On a practical note, when children are infected with measles, they must be kept out of school, forcing parents and their caregivers to miss time from work to care for them. In 2025, of the 2,267 measles cases, 11% resulted in hospitalizations, and three of these patients died. Moreover, 18% of children under 5 who were infected had to be hospitalized. All such data demonstrates that measles is more than just a benign infection.

Cases of measles are now surfacing at Immigration and Customs Enforcement (ICE) detention facilities in Arizona and Texas. Given measles’ high basic reproduction number, R0, which measures the average number of new infections that a single infected person can spread in a completely susceptible population, dozens more cases are certain to be reported in the coming weeks.

What makes the uptick in measles cases so concerning is that it serves as the “canary in the mine shaft” for other vaccine-preventable infectious diseases. Measles is the most transmissible infectious disease that children contract, with its R0 value between 12 and 18. Other infectious diseases with high R0 value include polio (12 to 17) and rubella (10-12).

RFK Jr. fuels vaccine hesitancy

People attribute this surge in measles cases to vaccine hesitancy, which has been exacerbated and fanned by the Health and Human Services secretary, Robert F. Kennedy Jr., who has a long history of marginalizing the use of vaccines to prevent diseases. He has continued to promulgate his personal beliefs and agenda by revamping the CDC and its Advisory Committee on Immunization Practices. Though vaccine hesitancy is certainly part of the risk calculus driving higher numbers of infections, the number of people who continue to get vaccinated and support vaccination for their children remains high, albeit not as high as it was six years ago.

The advisory committee also recently revamped the childhood immunization schedule, aligning it more closely with Denmark’s schedule. This resulted in six fewer diseases covered on the U.S. schedule. The change instituted by the advisory committee that impacted measles was the change at 12 months through 3 years, that the varicella vaccine should be given separately from the measles, mumps, and rubella (MMR) vaccine.

Much of the changed attitudes towards childhood vaccines appear to be driven by circulating misinformation about vaccines and a decline in trust in health authorities. Non-medical vaccine exemptions for school attendance have been on the rise, creating pockets of disease outbreaks and making it more difficult for school districts to achieve herd immunity.

Multiple decades of success with pediatric vaccines to protect against the plethora of childhood infectious diseases have confirmed their effectiveness and safety. Studies have shown that money invested in childhood immunization has a positive return. Unfortunately, falsehoods and hesitancy about the COVID-19 vaccines fueled vaccine hesitancy against all vaccines, even those that have been well accepted for many decades.

The American Academy of Pediatrics took it upon itself to issue its own recommended childhood immunization schedule, closely aligning with the schedule that was eliminated by the Advisory Committee on Immunization Practices. In addition, the American College of Physicians supports the previous 2025 advisory committee recommendations.

These are no ordinary times when it comes to immunization. Vaccines developed over the past 70 years have prevented numerous infections and saved countless lives. Returning to earlier times when children routinely were infected with numerous childhood diseases is not a formula for healthy living. The best advice that parents can take is to look to professional medical societies that have an established record of supporting health and healthy living and allow them to become the beacon of guidance for protecting your children and yourself. Indeed, the lights of reliable guidance and recommendations that once shone from the CDC have tragically gone dark.

Sheldon H. Jacobson, Ph.D., is a computer science professor in the Grainger College of Engineering at the University of Illinois Urbana-Champaign. As a data scientist, he uses his expertise in risk-based analytics to address issues impacting public policy and public health.

 Janet A. Jokela, M.D., is an infectious disease and public health physician, and clinical professor at Carle Illinois College of Medicine at the University of Illinois Urbana-Champaign.  She serves as a member of the Illinois Immunization Advisory Committee.