Measles is making a comeback. What does that mean for Los Alamos?
Editor’s note: As of June 27, 2025 the number of confirmed cases in New Mexico has risen to 86, with five new cases reported in Luna County.
Olivia, my eldest daughter, caught measles when she was seven years old…in an hour, she was unconscious. In twelve hours, she was dead.
The measles had turned into a terrible thing called measles encephalitis and there was nothing the doctors could do to save her. That was twenty-four years ago in 1962, but even now, if a child with measles happens to develop the same deadly reaction from measles as Olivia did, there would still be nothing the doctors could do to help her.
–Roald Dahl (1988)
Although measles was considered to have been eliminated in the U.S. in 2000, it has returned to North America this year with a vengeance, resulting in over 1,200 infections and three deaths to date. No cases have been reported in Los Alamos so far, but our proximity to large outbreaks in West Texas and eastern New Mexico means we shouldn’t let our guard down.
The first confirmed U.S. measles case in the 2025 West Texas outbreak was confirmed Jan. 23 in an unvaccinated child in Gaines County. The child was a member of the Old Colony sect of the Mennonite Church, which has a large presence in West Texas. While many Mennonite sects are not opposed to vaccines, the Old Colony sect traditionally shuns contemporary medical care and thus has a lower vaccination rate. This has allowed for community spread from West Texas.
Laboratory tests show that the measles cases in the Mexican border state of Chihuahua likely originated in West Texas. Canada has also been dealing with a measles epidemic that is thought to have begun at an Old Colony Sect gathering that took place in New Brunswick Province in October 2024, and preliminary indications are that the U.S. cases may have originated there as well.
New Mexico saw its first confirmed case on Feb. 11 in Lea County when state health officials reported that an unvaccinated teenager tested positive. New Mexico had two confirmed measles cases in 2024, which were the first in the state since 2021.
As of June 20, the vast majority of the 81 confirmed measles cases in New Mexico were in Lea County, which borders Gaines County, Texas. Six other counties have also had confirmed measles cases, with a statewide total of seven hospitalizations and one death. As a comparison, Texas has had 750 confirmed cases, 100 hospitalizations, and two deaths as of June 17.
As of June 13, potential exposures have been reported in Bernalillo, Sandoval, and Santa Fe counties after two travelers were diagnosed with measles during a visit to New Mexico. Another potential exposure took place in March from an infected, unvaccinated Texas traveler who visited Guadalupe and Valencia counties.
Positive wastewater sampling detections were found in Roswell on June 3, and in Deming on June 10. While the presence of the measles virus in wastewater is not considered a confirmed measles case, it shows that the disease may have some presence in the county and could spread to others soon. (Los Alamos's wastewater surveillance program is not affiliated with the NMDOH effort and does not currently provide data pertaining to measles.)
The outbreak has slowed since its beginning in late February, but health experts and officials still emphasize community and vaccine preparedness as the virus continues to spread throughout the U.S.
What is measles?
Measles is thought to be one of the oldest diseases to affect humans. Researchers believe the virus that causes measles in humans evolved zoonotically from the now-eradicated virus that caused Rinderpest disease, another eradicated virus that affected cattle. The historic timing of this divergence may even date back to the rise of cities in the 6th century BCE.
The measles virus, part of the Morbillivirus family, is extremely contagious and spreads easily through airborne respiratory droplets which can remain infectious for many hours. A single infected individual can spread the disease to 90% or more of their unprotected close contacts. Measles also has potentially serious side effects. Like most viral diseases, measles has no specific treatment or cure, and any treatment focuses on alleviating symptoms.
Symptoms typically begin 10-14 days after exposure to the virus and can initially include runny nose, cough, red and watery eyes, and an extremely high fever. Small white patches, known as Koplik spots, appear inside the cheeks 2-3 days after the initial symptoms, followed by a red rash that appears 3-5 days after the initial symptoms. The rash typically starts on the face and spreads to the rest of the body over the next few days. The period of maximum contagion is four days before this rash appears and up to four days afterward.
Most infected people recover from the disease within 10 days and suffer few lasting impacts. However, 20% of unvaccinated people who contract measles will be hospitalized. The risk for complications is high, particularly in children younger than 5 years old, adults over 20 years old, pregnant women, and immunocompromised people.
These complications can include:
Ear infections.
Diarrhea and associated dehydration.
Pneumonia, croup, and other severe respiratory problems.
Acute encephalitis (brain swelling, possibly resulting in brain damage.
Pregnancy complications, including premature or low-weight births and miscarriage.
Measles can also result in subacute sclerosing panencephalitis (SSPE), a debilitating and fatal neurological disorder that takes years to manifest. Children who contract measles before age 2 are especially susceptible to SSPE.
Treatment and prevention
According to the World Health Organization, “Community-wide vaccination is the most effective way to prevent measles. All children should be vaccinated against measles. The vaccine is safe, effective and inexpensive.”
In 1963, biomedical scientist John Enders and his colleagues developed the first measles vaccine, based on a live attenuated strain of the virus known as Edmonston-B. An improved version with reduced adverse reactions — the Edmonston-Enders strain — was developed in 1968 and has been the only measles vaccine distributed in the country since. A second dose of the vaccine became recommended after a significant U.S. outbreak in 1989.
The first dose of the vaccine is administered at 12-15 months of age and the second at 4-6 years old. It is typically combined with vaccines for mumps and rubella, known as MMR. For children between 12 months and 12 years of age, it can also be combined with the chickenpox (varicella) vaccine as MMRV.
Those who have had measles before are considered immune. As the disease was so rampant before the first vaccines were developed, adults born before 1957 are also presumed to be immune through childhood exposure. Individual immunity can be confirmed through blood tests.
A single dose of the measles vaccine is about 93% effective — for every 100 vaccinated people exposed to the virus, seven will contract measles. The second dose increases effectiveness to 97%. Breakthrough infections, when vaccinated people become infected, may still occur, but the vaccine reduces the severity and level of complication.
Vaccines provide individual protection, but high community vaccination rates also result in “herd immunity” by eliminating pathways for a disease to spread through a community. This is particularly important for ensuring that groups of people who cannot receive the vaccine — infants, pregnant women, and people with compromised immune systems — are still protected. The vaccination rate required to achieve herd immunity depends on the infectiousness of the disease, but for measles, it is 92-94%.
The full protective effect of the vaccine may not be realized until a month after it is administered. However, administering the MMR vaccine within three days of exposure, or immunoglobulin therapy within six days of exposure, can mitigate or even prevent infection.
The vaccines are considered to be extremely safe, with only minor side effects. A concern that the MMR vaccine caused autism arose from a study published in 1998 by Andrew Wakefield, but it has since been retracted and discredited. However, certain groups of people — including pregnant (or soon-to-be pregnant) women, immunocompromised people, and those with known allergies to vaccine components — should not receive the vaccine.
Vitamin A supplements have also been falsely touted as being protective against measles. However, while mostly not harmful, taking too much vitamin A can result in complications, especially in pregnant women. An increased number of children, particularly in Texas, were reported to have toxic levels of vitamin A during the measles outbreak this year.
Vaccines are required by law for all children entering school in New Mexico. The state permits medical and religious exemptions but, unlike many others, does not allow philosophical or personal ones.
New Mexico as a whole has a higher vaccination rate than most other states, and according to NMDOH, the rate of vaccination in Los Alamos schools (public and private) are likely high enough to prevent a measles outbreak.
What does this mean for Los Alamos?
No cases of measles have been reported in Los Alamos as of June 20. However, as summer travel picks up for both Los Alamos residents and visiting tourists, so does the probability for measles exposure in our community. The disease is highly contagious and not curable, and community wide vaccination efforts are the primary method for mitigating further spread.
The New Mexico Department of Health provides weekly updates on statewide cases on their website. Individuals can also access their vaccine records, although vaccines received in other states are not reflected. Some state health clinics in other counties are open for walk-in MMR vaccine appointments, and some vaccine clinics have been scheduled across the state.
Los Alamos physician Dr. Michelle Carr noted that while mass vaccination clinics aren't being offered currently in Los Alamos, doctor's offices and pharmacies can administer any vaccine recommended by the Centers for Disease Control and Prevention, including both MMR doses. The Los Alamos Public Health Office and El Centro Family Health Clinic in Española also offer vaccinations, and in some cases, at reduced or no cost.
“I would really encourage people to get vaccinated if they need to,” Carr said, “because some people can’t get vaccinated, and it’s not fair to them.”
All school-children who have not yet had a measles immunization should beg their parents to arrange for them to have one as soon as possible. Incidentally, I dedicated two of my books to Olivia, the first was ‘James and the Giant Peach‘. That was when she was still alive. The second was ‘The BFG‘, dedicated to her memory after she had died from measles. You will see her name at the beginning of each of these books. And I know how happy she would be if only she could know that her death had helped to save a good deal of illness and death among other children.
– Roald Dahl
Further reading and information
The CDC publishes national-level information about the current measles outbreaks
The CDC also has a page on the history of measles.
The New Mexico Department of health publishes information on state-wide conditions, as well as information on vaccine availability.
Everything you want to know about the medical science of measles can be found in the measles chapter of the American Academy of Pediatrics 2024–2027 Report of the Committee on Infectious Diseases.
The World Health Organization considers measles to be a significant international health issue.
Richard Skolnik
11h
Edited
This is a valuable article, for which I thank the authors. However, a few points need clarification. This article, like so many others, fails to note that NM has had a higher rate of infection than Texas. We should be acting on this basis in NM, rather than talking about how our immunization coverage is higher than in Texas. Second, SSPE CAN occur and it is almost always fatal. However, it occurs in only 4-11/100,000 cases of measles. The line about "immune suppression and amnesia" may confuse people. It would have been better to have said "immune suppression and Immune amnesia" and explained the latter, since few people know what it is.