Exeldy Perez, a licensed vocational nurse at Harris County Public Health & Environmental Services, holds a single dose of the MMR II vaccine.
Peter Hotez, M.D., Ph.D. is Peter Hotez, M.D., Ph.D., the Texas Children’s Hospital Endowed Chair in Tropical Pediatrics and the director of the Texas Children’s Hospital Center for Vaccine Development at Baylor College of Medicine.
2000: Endemic measles declared eliminated in the U.S. (Measles virus particle, credit: CDC/Cynthia S. Goldsmith; William Bellini, Ph.D.)

Bracing for Measles

Is Texas poised for an outbreak?

See All Photos

Bracing for Measles

13 Minute Read

The spots started on the back of his neck. Ariel Loop’s 4-month-old son, Mobius, was battling his first illness. His fever was 102 when Loop noticed the telltale rash—flat red spots that started on his head and gradually spread throughout his body.

“I thought I was crazy. There’s no way,” Loop said, laughing incredulously. Even two years later, the experience is surreal. Loop, a nurse, knew some of the signs of the measles, but they didn’t spend much time studying it in nursing school, she said. She never expected to see cases of an eliminated disease, let alone in her own child.

The Loops had taken their son to Disneyland a couple of weeks earlier, in mid-January 2015. Living in Pasadena, California, Disneyland was a regular destination. Ariel and Christopher Loop were married there. It’s where they announced they were expecting Mobius, and it was only a matter of time until they visited the park as a family.

As the spots spread and the fever wouldn’t break, reality sank in: Mobius had caught the measles at Disneyland. Knowing how contagious the disease is, the couple called ahead to warn the emergency department of their local hospital. They were ushered through a back door and whisked into a negative pressure room where their infant was treated by doctors and nurses in protective gear—medical experts who had never seen measles in person.

The hospital did bloodwork, warned them of complications and sent them home under quarantine. Four days later, the test came back positive for measles.

One of the most contagious diseases

Distill the threat of measles down to its quantitative essence and you’re left with a number between 12 and 18. That’s its R0, or basic reproduction number. On average, one person with the measles will infect 12 to 18 others. Each one of those people infects a dozen or more, and each one of them infects another dozen. That’s how an epidemic begins. One cough or sneeze sends the measles virus airborne. There it can linger, able to infect for up to two hours. The R0 of influenza? Two to three. The R0 of SARS, the respiratory illness that in 2003 infected more than 8,000 people worldwide? Two to five.

Measles is one of the most contagious of all infectious diseases, but the development of a vaccine in the 1960s led to dramatically decreased rates of infection. It was officially declared eliminated in the United States in 2000. In the years since, however, misinformation about the safety of vaccines has caused immunization rates to reach dangerous lows in a number of places throughout the country, including some areas in Texas. A recent outbreak among unvaccinated people in Minnesota has public health experts wondering if Texas could be next.

“We’ve got about 50,000 kids whose parents have opted them out of getting vaccinated for non-medical reasons, and this has accelerated precipitously,” said Peter Hotez, M.D., Ph.D., dean of the National School of Tropical Medicine at Baylor College of Medicine and president of the Sabin Vaccine Institute and Texas Children’s Hospital Center for Vaccine Development.

Non-medical reasons to forgo vaccinations—known as conscientious exemptions—are often based on religious or philosophical beliefs.

The key to preventing measles from spreading is “more than 95 percent immunity through a two-dose vaccination regimen,” the World Health Organization says. In the 2015-16 school year, 97.6 percent of Texas kindergarteners had received both doses of the measles, mumps and rubella vaccine (MMR), according to the Texas Department of State Health Services. While this is above the recommended rate, the number of exemptions still poses a threat, because unvaccinated children are not spread evenly throughout the state.

“They tend to be concentrated more in the Travis County, Austin area and around Denton, Texas,” Hotez said. “I think that’s where we’re going to start seeing measles outbreaks.”

When more people are immune to a disease through vaccination, it’s more difficult for the disease to spread. High vaccination rates protect those who can’t be vaccinated for health reasons, a concept called herd immunity. Low vaccination rates threaten herd immunity and put vulnerable communities—children too young to be vaccinated, individuals with compromised immune systems, people who are severely allergic to certain vaccines—at risk.

“It’s a global economy, and higher immunization rates are safeguards to keep us from being susceptible to these diseases,” said Brian Reed, M.D., director of disease control and clinical prevention at Harris County Public Health and Environmental Services. “Parents may be thinking they’re doing the right thing for their child, but they’re inadvertently harming the community.”

The consequences of reducing herd immunity can currently be seen in action in Minnesota, where a measles outbreak has been spreading since April.

Minnesota-Austin connection

Like all epidemics, the Minnesota measles outbreak started out small. In early April, Hennepin County reported three cases of the disease. Two months later, that number has grown to about 70—the worst outbreak the state has seen in 30 years. Like Texas, Minnesota’s vaccination rates are over 90 percent. The current outbreak can be traced to a Somali immigrant community in Minneapolis, where the vaccination rate in 2014 was reported to be 42 percent—a significant decrease since 2008, when the same community had some of the highest vaccination rates for two-year-olds in the state.

This swift decline is a result of targeting by anti-vaccine advocates. Most notable: Andrew Wakefield, the British doctor who rocked the medical community with his 1998 paper, published in The Lancet, claiming a link between autism and the MMR vaccine.

In 2010, the U.K. barred Wakefield from practicing medicine and The Lancet formally retracted his paper, but the damage had been done. Despite numerous studies debunking the link between autism and vaccines, the myth persists. Wakefield continues to campaign against vaccines and parents continue to listen. In 2008, he visited the Somali-American community in Minneapolis, and vaccination rates have been decreasing ever since.

When questioned by The Washington Post regarding the recent outbreak, Wakefield said he was simply providing information about vaccines and autism.

“The Somalis had decided themselves they were particularly concerned. I was responding to that,” he said. “I don’t feel responsible at all.”

What does an outbreak in Minnesota have to do with Texas? Although Wakefield travels the country promoting his anti-vaccine agenda, he lives in Austin. He speaks at anti-vaccine rallies on the steps of the state capitol building, and he holds screenings of his film, Vaxxed: From Cover-Up to Catastrophe, throughout the state. Meanwhile, non-medical vaccine exemptions have increased since 2003, when the state enacted some of the loosest vaccine exemption laws in the country. At least one private school in Austin has an exemption rate of more than 40 percent.

“In 2003, we had less than 5,000. In 2016 we had 45,000 to 50,000 exemptions,” said Richard Lyn-Cook, M.D., medical director of Harris Health School-Based Clinics and assistant professor at Baylor College of Medicine. “It just takes one person to come in contact with a traveler who was not vaccinated and can spread it to a child less than one, the most vulnerable population.”

A common refrain among vaccine critics is that the measles is not dangerous. Robert “Dr. Bob” Sears, M.D., a California pediatrician and high-profile proponent of “alternative” vaccine schedules, wrote in a Facebook post: “Ask any grandma or grandpa (well, older ones anyway), and they’ll say, ‘Measles? So what? We all had it. It’s like chicken pox.’”

Lyn-Cook has a different take.

“About 50,000 were hospitalized per year before the vaccine,” he said. “It was unbelievably dangerous to our population, and if we were hospitalizing 50,000 kids a year for a different disease it would be a national disaster.”

Internationally, 2017 has been a bad year for measles. In Europe, the largest outbreaks have occurred in Romania and Italy. According to the European Centre for Disease Prevention and Control, most immunization rates in affected areas have fallen below the 95 percent threshold due to skepticism about the vaccine. Some locations have extenuating circumstances. In Guinea, where a full-scale epidemic is raging, vaccinations dropped during the 2014-2015 Ebola epidemic, according to Doctors Without Borders. Vaccination activities were suspended due to the risk of infection.

(Click to enlarge)


The most common symptoms of measles are a high fever, cough and runny nose. Three to five days later, a rash breaks out, starting on the face and head and spreading downward. Fever can spike to over 104 degrees.

Children under five and adults over 20 are most likely to experience complications from measles. One in every 10 children will develop an ear infection, which can result in permanent hearing loss. One in every 20 children will develop pneumonia, the most common cause of death from measles. One in 1,000 will experience encephalitis, brain swelling that can leave a child with lifelong disabilities.

The most serious complication is subacute sclerosing panencephalitis (SSPE), a progressive, deadly brain disorder. SSPE takes seven to 10 years to develop after contracting measles. Throughout those years, the person may seem fully recovered, until symptoms like forgetfulness, unusually poor school performance and sudden personality changes appear. It is most common in children who contracted measles under the age of 2.

While SSPE is rare, recent studies have shown it is not as rare as once thought. Original estimates had it affecting 1 in 100,000. A study of cases stemming from a major measles outbreak in California in the late 1980s indicates 1 in 1,400 children under five and 1 in 600 infants under age 1 later developed SSPE.

“Measles is a killer infection, and the ones who are the most vulnerable are infants below the age of 1 who are not eligible to receive the vaccine,” Hotez said. “Those are the ones who are going to get sick, and those are the ones who could die.”

Ariel Loop’s son, Mobius, recovered from his bout with measles. Today, he is a happy toddler who is developing normally. But Loop still worries about SSPE.

“I have to worry about that for such a long time,” Loop said. “I know it’s a pretty rare complication, but it’s hard not to think about that sometimes, that he could drop dead out of nowhere in the next 10 years.”

After Mobius recovered, Loop had a new mission: lobbying California state lawmakers to require all schoolchildren to be vaccinated barring any medical issues. She testified before California legislators, and Senate Bill 277 was signed into law June 30, 2015. Within two years, the measles vaccination rate among the state’s kindergarteners had risen from a dangerously low 92.6 percent in 2014 to 97.3 percent in 2016.

“It’s the silver lining,” Loop said. “Ultimately, the goal is to prevent other children from having to go through this. I’m glad that something positive has been able to come from it.”

Texas lawmakers debate vaccines


Vaccines have been a hot topic among Texas lawmakers in 2017. House Bill 1124 proposed granting parents the ease of filing for an exemption online. It was an alarming step in the wrong direction for health experts.

“Well-meaning people are introducing measures for more freedom for exemptions,” Lyn-Cook said. “That may work for some things but it doesn’t work for vaccination. That’s like saying it’s optional for you to wear a seatbelt.”

Lindy McGee, M.D., a Texas Children’s Hospital physician and assistant professor at Baylor College of Medicine, is co-chair of the physician advisory board of The Immunization Partnership. As part of the organization’s goal “to eradicate vaccine-preventable diseases by … advocating for evidence-based public policy,” McGee testified against HB 1124 in front of the House Committee on Public Health.

“Plenty of data from other states show that anything you do to allow exemptions to be easier increases the rate of unvaccinated children,” McGee said. “We are extremely concerned about any legislation that would make it easier to get an exemption.”

During the meeting, she was grilled by committee member Rep. Bill Zedler, who claimed more people have died from the measles vaccination than from the measles. Zedler reached this conclusion by comparing data about vaccine injuries from the Vaccine Adverse Event Reporting System (VAERS) to CDC data about measles deaths.

As McGee pointed out, however, anyone can report an “adverse event” to the VAERS database, which is run by the CDC and the Food and Drug Administration. On the VAERS website, the CDC notes: “studies help determine if a vaccine really caused an adverse event. Just because an adverse event happened after a person received a vaccine does not mean the vaccine caused the adverse event.” In other words, correlation does not equal causation.

“I could break my arm the next day and I can report that to that reporting system,” McGee explained to Zedler. “It’s not necessarily due to the vaccine.”

Zedler responded, “For you to get up and tell this committee in essence they can put anything down there they want is quite dishonest.”

McGee said she sent documentation the next day that supported everything she said in her testimony.

“It’s frustrating to go to the legislature to argue facts,” she said. “I am always happy to answer a parent’s legitimate concerns about vaccines. My frustration is with people on the public health committee who are supposed to be protecting public health.”

The Immunization Partnership also lobbied for House Bill 2249, known as the “parents’ right to know” bill. This bill would have required the state to report vaccination exemption data at the individual school level rather than the school district level.

“We want parents to know how their school is doing in terms of vaccine coverage so they can make an informed choice,” Hotez said. “If they see vaccine coverage is very low at their school, they can decide, ‘This school isn’t safe for my child.’”

McGee noted that in addition to helping parents make informed school choices, House Bill 2249 “would help us as vaccine educators to know which schools to target and figure out what’s going on if the rates are low.”

But the bill died in the House on May 11.

Protecting Harris County

Lack of legislative action regarding vaccines is challenging for the medical and public health experts who know all too well what will happen if the anti-vaccine movement gains more traction.

“We need our elected leaders to talk about the importance of vaccinating and why there’s no link between vaccines and autism,” Hotez said. “We don’t really hear from the Office of the Surgeon General. We don’t hear from the White House.”

While vaccine-related bills stall in the state legislature, medical and public health professionals in Houston do what they can to protect the community. Organizations like Harris Health System, Texas Children’s Hospital and Harris County Public Health and Environmental Services (HCPHES) maintain mobile health clinics to provide vaccinations at schools, community and WIC centers, and other locations throughout the county.

HCPHES officials also discuss what actions they would take in the event of a measles outbreak in Harris County.

“We would have additional resources to provide immunizations to people who have had contact with someone who has active measles and those at higher risk,” Reed said. The high-risk group includes pregnant women, immunocompromised individuals and young children.

A measles vaccine may still prevent the disease after an unvaccinated person has been exposed to it, if the vaccine is given within 72 hours, Reed explained. Immune globulin, a blood product containing antibodies that the county would also offer to vulnerable citizens, can lessen the severity of the disease if given within six days of exposure.

In terms of advocacy and awareness, groups like The Immunization Partnership campaign for legislation to promote vaccination and work to educate and encourage parents.

“We offer webinars and toolkits on increasing immunization rates and also work with school nurses,” McGee said. “A grassroots parents campaign is working to counteract anti-vaccine groups in the state and raise awareness.”

While medical professionals do what they can to provide vaccine access, education and resources, there are still parents they can’t reach. The ones convinced through their internet research that vaccines are dangerous. The ones who trust Andrew Wakefield over licensed pediatricians. Like all parents, they want what is best for their children. After seeing measles infect her child, Ariel Loop has advice for them.

“Trust people who have spent their lives focusing on this,” she said. “As helpful as Google can be, it’s not the same thing as going to school for a decade. Find people who are experts, and trust science. It’s science—it’s not an opinion.”

Back to top