Measles: Vaccine-Preventable Disease Returns

In 2000, public health officials declared measles eliminated from the United States. The disease that once killed 400-500 annually in the U.S. had been vanquished thanks to a safe and highly effective vaccine. Measles cases in the U.S. dropped from millions each year to almost none. Vaccination became one of the greatest public health success stories in history, protecting not just the children who received it but entire communities through herd immunity — resistance to the spread of an infectious disease because of pre-existing immunity in a high proportion of individuals.

But in 2025, measles has returned with a vengeance. Outbreaks have swept across parts of the country, with more than 1,000 confirmed cases and several deaths, most among unvaccinated children. The virus we thought we had conquered has returned to remind us just how dangerous complacency can be.

Measles is not a mild childhood illness, as some would like to believe. It is among the most contagious viruses known. If one person is infected, up to 90 percent of the unvaccinated people close to them will also become sick. One in five requires hospitalization. Ear infections and pneumonia are common complications, causing permanent hearing loss in some. About one in a thousand develops encephalitis — a dangerous inflammation and swelling of the brain that can leave lasting damage or even become fatal. The virus still kills more than 100,000 around the world every year.

So distressing to me as a physician is the tragedy of today’s outbreaks that are entirely preventable. The measles, mumps, and rubella (MMR) vaccine has been in use for more than 50 years. Two doses provide around 97 percent protection against the disease. Side effects are usually minor, and serious reactions are exceedingly rare.

But if the vaccines are so successful, why are we seeing a measles recrudescence? Because of declining vaccination rates.

In some communities, skepticism about vaccines has spread faster than the virus itself. Myths persist that vaccines are unsafe, overloaded with chemicals, or linked to autism — claims that have been thoroughly and repeatedly disproven by scientific studies. Despite this evidence, Florida plans to end its vaccine mandates to attend school.

Actions like these create mistrust that lingers, fueled by misinformation on social media, political polarization, and a broader erosion of faith in public institutions. When vaccination rates fall below about 95 percent, measles quickly finds opportunities to return. That is exactly what is happening now.

Some people cannot be vaccinated — infants under 12 months, people with certain medical conditions, and those with compromised immune systems — but the vast majority can be vaccinated. When we vaccinate ourselves and our children, we don’t just protect our families, but also our neighbors, our schools, and our communities. Vaccination is an active social responsibility, akin to stopping at a red light or not smoking near nonsmokers.

Individuals who refuse to be vaccinated do not just make an individual choice; they open cracks in the wall of herd immunity, allowing the virus to sneak in.

The measles outbreak of 2025 is a wake-up call. We cannot take the victories of public health for granted. The same science that once eliminated measles from the United States still works today. What has changed is our willingness to use it.

This article is featured in the November/December 2025 issue of The Saturday Evening Post. Subscribe to the magazine for more art, inspiring stories, fiction, humor, and features from our archives.