After Hundreds of Infections and Two Deaths, Texas Declares End to Its Measles Outbreak

Texas health officials declared on Monday that the measles outbreak that has sickened more than 700 people in the state and killed two children is over—though they warned that the threat posed by the disease is not.

It’s been more than 42 days since a new measles case has been reported in the West Texas outbreak that began in late January, according to the Texas Department of State Health Services (DSHS). Public health experts generally consider that to be the marker of the end of a measles outbreak, DSHS said, because 42 days is double the maximum amount of time it can take for a person to show symptoms of measles after being exposed to the virus.

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There have been 762 confirmed measles cases in the state this year, as of Monday, according to DSHS. The outbreak began in undervaccinated Mennonite communities in Gaines County, and was later linked to measles cases in other states, including New Mexico and Kansas. Two unvaccinated girls in Texas died of measles-related causes earlier this year.

In announcing the end of the Texas outbreak, DSHS applauded the state’s health care professionals, many of whom had never seen a measles case before this year, for their work. But the department also warned: “The end of this outbreak does not mean the threat of measles is over.”

Measles is highly contagious and can be fatal, though it is vaccine preventable through the measles, mumps, and rubella (MMR) vaccine. The disease was declared eliminated from the U.S. in 2000, an achievement public health experts largely attributed to a successful vaccination program. But MMR vaccination rates have declined in recent years, and measles cases have increased. This year, largely due to the Texas outbreak, the number of measles cases hit a 33-year record high in the U.S.

Read More: Do You Need a Measles Vaccine Booster?

As of Aug. 5,  there have been 1,356 confirmed measles cases across the country this year, according to the Centers for Disease Control and Prevention (CDC). Of those, 92% were people who were either unvaccinated or their vaccination status was unknown. In total, there have been three confirmed measles deaths this year: the two unvaccinated children in Texas, and one unvaccinated adult in New Mexico. Before this year, the last time a person was known to have died of measles-related causes in the U.S. was in 2015.

Dr. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, says that it’s reasonable to say that the current Texas outbreak has subsided based on the available data. But he also expresses concern that the official figures are undercounts. Many people in the Mennonite community typically don’t seek medical care, he says, so it’s possible that some people contracted measles who public health officials weren’t aware of. Offit also criticizes the Trump Administration’s cuts to the CDC, which he worries could have affected the agency’s ability to track cases.

Historically, Offit says, measles cases have peaked in the winter months and abated in the spring and summer months, so he fears that the numbers will increase again in a few months.

“I don’t think this is the end at all,” Offit says. “This should be a warning to parents that, if they haven’t vaccinated their children, that now’s the time.”

Concerns about the potential consequences of declining vaccination rates extend beyond measles, as well. Because measles is one of the most contagious viruses, it’s often the first to experience a resurgence when vaccination rates fall, public health experts have told TIME, cautioning that the rise in cases could be a sign that other diseases may become more prevalent too. 

Offit also says that getting measles causes “immune amnesia,” meaning that after being infected with the disease, a person is more susceptible to other pathogens—even ones that the person’s immune system was able to fight off before.

Offit calls the Texas outbreak “a warning shot.” The outbreak, he says, showed that many parents have chosen not to vaccinate their children against measles—and the consequences of that.

“On the one hand it’s fine to say that the fear that we all have now can be relaxed by the fact that the virus doesn’t appear to be spreading now [in Texas],” Offit says. “But really, I think the messaging should be one of: that was a warning shot, and several people, including two little girls, paid the price.”

“We can’t let that happen again,” he continues. “It’s unconscionable to have a child die of something that is entirely preventable.”