Measles outbreak that sickened more than 700 declared over in Texas

The outbreak led to the deaths of two school-aged children.

A measles outbreak in Texas that infected more than 700 people has officially been declared over, state health officials announced on Monday.

The outbreak was the largest in the state in more than 30 years and led to the deaths of two unvaccinated school-aged children.

Health officials declared the outbreak over after more than 42 days without a new case, a cut-off based on the time between when a person is exposed to when they get sick.

In late January, a cluster of cases was reported in western Texas near Gaines County -- near the border with New Mexico -- which had one of the lowest vaccination rates in the state.

A total of 762 cases were recorded with more than two-thirds of infections among children, according to the Texas Department of State Health Services (DSHS). Nearly 100 people were hospitalized.

Infections spread to other parts of the state as well as New Mexico, where another unvaccinated person died after contracting measles.

"I want to highlight the tireless work of the public health professionals across the state who contributed to the containment of one of the most contagious viruses," Dr. Jennifer Shuford, commissioner of the DSHS, said in a press release. "We arrived at this point through a comprehensive outbreak response that included testing, vaccination, disease monitoring and educating the public about measles through awareness campaigns."

Texas health officials warned that the state is likely to experience additional cases this year given ongoing outbreaks in other parts of the U.S. and the world.

"The end of this outbreak is certainly encouraging, but measles remains one of the most contagious viruses we face, and continued vigilance is critical given ongoing outbreaks both in the U.S. and globally," said Dr. John Brownstein, an epidemiologist and ABC News medical contributor.

Nationally, over 1,350 cases of measles have been reported across at least 40 states, according to the Centers for Disease Control and Prevention (CDC). It is the highest number of measles cases seen in the U.S. since 1992.

The virus was declared eliminated by health officials in 2000 after a full year of no continuous spread, but declining vaccination rates have led to a growing number of outbreaks annually, experts say. An estimated 92% of cases nationally this year are unvaccinated or have unknown vaccination status.

"Vaccination rates in many communities remain far too low, leaving large pockets of children vulnerable to measles and other preventable diseases -- and that's why we're likely to continue seeing outbreaks," Brownstein said.

The 2024-2025 school year had a record number of non-medical vaccine exemptions, with an estimated 286,000 kindergarteners attending school without documentation of receiving the shot that protects against measles, according to CDC data.

"Measles isn't happening in isolation -- we're seeing a broader resurgence of vaccine-preventable diseases, from pertussis to polio threats, which underscores the urgent need to maintain high vaccination coverage and public trust in immunization," Brownstein added.

The measles, mumps and rubella (MMR) vaccine is recommended for children in the U.S. to receive after their first birthday, followed by a second dose in between ages four and six. Two doses of the vaccine have been shown to be 97% effective against infection.