Little girl with measles.
In less than three weeks, a measles outbreak has jumped from two cases among unvaccinated children in West Texas to 48. Three cases have also been found in a neighboring county in New Mexico. Thus far, 13 children have been hospitalized. Vaccine-preventable diseases such as measles remain a public health threat. And with childhood vaccine hesitancy—or simply outright refusal—on the rise, the problem is likely to worsen.
The measles case count in Texas and New Mexico likely represents a fraction of the true number of infections. Health officials suspect that between 200 and 300 people are infected but untested. The cases in West Texas appear to trace back to unvaccinated members of a Mennonite community.
As numbers of unvaccinated across the United States increase along with lower levels of overall herd immunity, we will inevitably see more outbreaks. At least 20 schools across Texas have vaccination rates for the measles, mumps, and rubella vaccine that are lower than 50%. And in 2024, the Centers for Disease Control and Prevention reported that for pupils entering kindergarten the rate of vaccination for all childhood vaccines fell below 93%, which is under the 95% threshold health experts say is necessary to prevent outbreaks.
This raises a much larger discussion around vaccines and vaccine uptake. Newly sworn in Secretary of Health and Human Services, Robert F. Kennedy, has expressed criticism of vaccines, citing what he views as possible safety issues. During his Senate confirmation hearing, Kennedy said he was not anti-vaccine. Rather, he stated, “I am pro-safety,” as he called for more studies to be done. Perhaps more troubling have been his false claims of links between the MMR vaccine and autism, which were discussed during the hearing, too.
The two-dose MMR vaccine is safe and highly effective at preventing illness. The full vaccine series is 97% effective against measles, but even one shot provides 93% effectiveness, according to the CDC.
If unvaccinated, being exposed to the highly contagious measles virus can lead to a person contracting the disease which causes an initial flu-like illness with symptoms that include a high fever of over 103 Fahrenheit (39.4 Celsius), copious congestion, red eyes and a rash that spreads around the entire body. About 20% of unvaccinated people who get measles end up hospitalized, the CDC said. One in 20 children who get it end up with pneumonia, the most common cause of death in infected children.
Patients with measles can also develop ear infections, severe gastrointestinal upset, pneumonia and brain swelling or encephalitis, which occurs in one in 1,000 children who contract measles. This can lead to deafness, convulsions, intellectual disabilities and death. Encephalitis is what killed author Roald Dahl’s seven-year old daughter, Olivia, in 1962. This was before the advent of vaccines.
In 1986, Dahl penned an essay about her death as an appeal to parents everywhere to vaccinate their children. Dahl wrote:
“Olivia, my eldest daughter, caught measles when she was seven years old. As the illness took its usual course I can remember reading to her often in bed and not feeling particularly alarmed about it. Then one morning, when she was well on the road to recovery, I was sitting on her bed showing her how to fashion little animals out of colored pipe-cleaners, and when it came to her turn to make one herself, I noticed that her fingers and her mind were not working together and she couldn’t do anything.
“Are you feeling all right?” I asked her.
“I feel all sleepy,” she said.
In an hour, she was unconscious. In twelve hours she was dead.”
Before widespread availability of vaccines in the 1960s, measles was the single leading killer of young children globally. Even in the U.S., an estimated 400 to 500 people died from measles annually then while 48,000 were hospitalized and 1,000 suffered encephalitis.
Measles was declared eliminated from the U.S. in 2000, which meant that at that time there was an absence of disease transmission for greater than 12 months. But that declaration turned out to be premature. While annual numbers of cases of measles in the 2000s were relatively small, they climbed to 1,274 confirmed cases in 31 states in 2019. This was by far the greatest number of cases reported in the U.S. since 1992.
Mass vaccination campaigns in many countries throughout the world have significantly reduced mortality around the globe. Based on estimates published in the journal The Lancet, the global number of measles deaths in 2020 was 60,700, a 94% decrease from 1,072,800 deaths in 2000, and a 98% drop from 2,600,000 deaths in 1980. However, from 2020 to 2022, measles fatalities worldwide more than doubled, reaching 136,000.
Today, between one and three of every 1,000 children who get measles die from respiratory or neurologic complications. Unvaccinated women who are pregnant can have babies born prematurely or low birthweight, which can cause long-term issues for a child’s development.
And, according to two studies published in 2019 in the journals Science and Science Immunology, measles can inflict more harm than just the acute infection. The virus can eliminate acquired immune memory by destroying the memory B, plasma and T cells, which in turn cause people to become much more susceptible to infections.
Measles isn’t the only vaccine-preventable disease that poses a public health threat. Others include polio, mumps, diphtheria, tetanus, whooping cough and hepatitis B. Childhood vaccine exemptions, both medical (due to contraindications) and non-medical, are now at an all-time high. And while still only about 3% of children have non-medical exemptions on religious or philosophical grounds, the number is now greater than 5% in 10 states, including Texas. If this continues to rise, we can expect to see more outbreaks.
