Many Kids Traveling Overseas Aren't Vaccinated Against Measles

Many American kids aren't vaccinated against measles before they travel overseas to areas where the disease is endemic, a new study finds.

Nearly 60% of these children hadn't received the measles-mumps-rubella (MMR) vaccination before going abroad. This year, the more than 1,200 cases of measles reported in the United States were largely the result of people returning from trips abroad and bringing the virus back with them.

"Providers should consider MMR vaccination for eligible children who will be traveling internationally, which includes destinations such as Europe," said lead researcher Dr. Emily Hyle. She is a clinician and investigator in the Division of Infectious Diseases at Massachusetts General Hospital in Boston.

"Parents and guardians should ask their pediatrician about MMR vaccination before international travel," Hyle added.

Although children traveling overseas make up only 10% of all international travelers, they account for almost 50% of all measles cases brought to the United States over the past 10 years, Hyle said.

Measles is on the rise again globally, with more measles cases reported in 2019 than in 2018, according to the World Health Organization, she said. Also, WHO reported more than 140,000 deaths from measles in 2018.

"We can do a better job of protecting vulnerable children by being sure that they have received MMR vaccination before possible exposure during travel," Hyle said.

The U.S. Centers for Disease Control and Prevention recommends that all kids get two doses of the MMR vaccine starting at between 12 and 15 months. The second dose is given between the ages of 4 and 6.

Because of the danger of getting measles outside the United States, the CDC's Advisory Committee on Immunization Practices recommends that kids between 6 and 12 months traveling overseas get one dose of the vaccine.

This single-dose doesn't count toward the two-lifetime doses. Also, kids aged 1 to 6 should get both MMR doses before leaving the country, the agency says.

One expert not involved with the study said parents may have incorrect assumptions about travel.
"I think that when people go to developed countries, like [in] Western Europe, they assume that they're going to a country like the U.S. where there isn't a risk for measles, but they are," said Dr. Paul Offit, director of the Vaccine Education Center at the Children's Hospital of Philadelphia.

They don't know that measles is endemic in Italy, France, Germany, and England, to name a few, and you have a fairly high likelihood of being exposed to measles, he said.

"I think that the reluctance to get vaccinated just comes from living in a country where measles isn't common," Offit said.

Measles was once thought to be almost eliminated in the United States, but cases have been increasing. This year's more than 1,200 cases are the most reported since 2000.

Fortunately, no one has died from measles in the United States this year, but if the number of cases keeps increasing, it's only a matter of time until deaths occur, Offit said.

In 1990, a measles outbreak in Philadelphia sickened some 1,400 kids and killed nine, he said. The cases and deaths were mostly among kids who hadn't been vaccinated.

The vaccine is both safe and effective against measles, which is the most contagious of the vaccine-preventable diseases, Offit said.

"In fact, a single dose provides 93% protection for the rest of your life," he said. The second dose provides 97% protection.

"It's an excellent vaccine, and it's safe, and no, it doesn't cause a lot of the things that people fear, like autism," Offit said.

For the study, Hyle and her team looked at data on kids' travel listed in the CDC's global travel clinics.

Of more than 14,000 kids listed from 2009 to 2018, 92% of infants and 60% of preschool children were eligible for the MMR vaccine.

Among these children, 44% of infants and 57% of preschoolers were not vaccinated. The lack of vaccination often occurred because doctors didn't know that these kids were eligible for the vaccine or the guardian refused the vaccine, the researchers found.

The report was published online Dec. 9 in the journal JAMA Pediatrics.

Sources: Emily Hyle, M.D., clinician and investigator, Division of Infectious Diseases, Massachusetts General Hospital, Boston; Paul Offit, M.D., director, Vaccine Education Center, Children's Hospital of Philadelphia; Dec. 9, 2019, JAMA Pediatrics, online.