A new study in Morbidity and Mortality Weekly Report from scientists with the Centers for Disease Control and Prevention (CDC) and their state partners analyzes the patients hospitalized during the first two months of the measles outbreak that swept through West Texas in 2025, finding that nearly all were unvaccinated children, only 11% had preexisting conditions, and respiratory complications were common.
From January 20 to March 18, 2025, 325 measles cases were reported in the region, and 60 patients—roughly one in five—were hospitalized. Of the 54 hospitalized patients with available medical records, all were either unvaccinated or had unknown vaccination status. The vast majority (49; 91%) were younger than 18 years, and 48 (89%) had no underlying health conditions. One patient died.
4 infected women were in third trimester of pregnancy
Complications were common: 39 patients (72.2%) developed pneumonia, 25 (46.3%) experienced dehydration, one (1.9%) developed hepatitis [liver inflammation], and one experienced febrile seizures. Seventy percent required supplemental oxygen.
Five hospitalized patients were adults, four of whom were pregnant and in their third trimester. None developed pneumonia or hypoxia (low blood oxygen levels), but two delivered infants during their hospital stays. Both newborns tested positive for measles within two days of birth.
“During these early months of the outbreak, approximately 20% of patients required hospitalization, a similar percentage to that reported during previous measles outbreaks,” the authors note, adding that the clinical characteristics, rates of complications, and outcomes for hospitalized patients were similar to those reported for previously hospitalized measles patients.
“The outcomes experienced by patients hospitalized during this outbreak underscore the seriousness of measles infection and highlight that measles can cause life-threatening complications affecting multiple organ systems,” add the authors.
Vaccination 97% effective at preventing disease
Measles is highly transmissible and can cause serious complications, especially in children aged 5 years and younger.
The disease was declared eliminated in the United States in 2000, but the number of cases has surged in recent years. In the first half of 2026 alone, the country has registered nearly 2,000 cases. The total number of cases for all of 2025 was 2,288. Earlier this week, Florida reported the highest number of cases in the state in a single year in the past 25 years.
The outbreak in West Texas, which became the largest US measles outbreak in years until South Carolina recorded 997 cases from October 2025 to March 2026, began in January 2025, when health officials identified a case in an unvaccinated school-aged child in Gaines County. By August, the outbreak had sickened 762 people. The outbreak was declared over on August 18, 2025—42 days after the onset of a measles rash in the last known patient.
Vaccination remains a critical tool for the prevention of measles infection and severe disease.
The authors say the findings highlight the importance of maintaining high measles, mumps, and rubella (MMR) vaccine coverage to prevent severe illness, hospitalizations, and deaths associated with measles outbreaks.
“Vaccination remains a critical tool for the prevention of measles infection and severe disease,” write the authors, noting that one dose of the vaccine is approximately 93% effective at preventing the disease, and two doses are 97% effective. In addition, measles cases that do occur in vaccinated people tend to be milder, posing a lower risk of serious complications.
