- Most young children are not fully vaccinated before going abroad, according to a new study.
- This comes as measles cases have spiked globally.
- Currently, an outbreak in Samoa has sickened 4,700 and led to 70 deaths.
This past October, the United States came shockingly close to losing its measles elimination status — an achievement the country reached in 2000 after bringing measles counts down after a widespread, effective vaccination campaign.
But within the past couple of years, measles cases have soared again, not only in the United States — where there was over 1,000 casesTrusted Source in the first half of 2019 — but across the world as well.
This makes a new study from Massachusetts General Hospital (MGH) especially worrying for public health officials. Researchers have discovered that even though most infants and preschool-age children were eligible for measles-mumps-rubella (MMR) vaccination before traveling, only 40 percent had been properly vaccinated prior to their departure.
The study, which published Monday in JAMA Pediatrics, reported that most of the pediatric travelers were not vaccinated due to guardian refusal or a clinician decision, even though recommendations from the Advisory Committee on Immunization Practices (ACIP) advise children get vaccinated before international travel.
The news comes amid a global uptick in measles cases. New estimate trusted Source from the World Health Organization predicts that over 140,000 people worldwide died from measles in 2018, most of whom were children under age 5.
It’s unfolding in Samoa now, where a fast-spreading outbreak has sickened close to 4,700 people and claimed 70 lives. Sixty-one out of the 70 deaths were children 4 and under, Reuters reported Sunday, due in part to the very low vaccination rates seen across the nation.
In the United States, most outbreaks can be traced back to international importation, in which a U.S. traveler was infected abroad and brought the virus back home.
While only 10 percent of U.S. international travelers are children, the young travelers accounted for nearly 47 percent of measles importations between 2001 and 2016.
Researchers from MGH studied pre-travel consultations from over 14,602 pediatric travelers, which was sourced from the Global TravEpiNet, an association of clinical sites in the United States.
Of the 14,602 children evaluated, 2,864 were eligible for pre-travel MMR vaccination. However, just 1,182 children, or 41 percent, received the necessary shots before traveling 59 percent did not.
Nearly 89 percent of eligible school-age children or 299 of 338, or those ages 6 to 18 years in this study did not get vaccinated.
About 44 percent of eligible infants (6 to 12 months old) and 56 percent of preschool-age children (ages 1 to 6 years) were not vaccinated.
The researchers found the most common reasons children were the clinician’s decision to not vaccinate the children along with guardian refusal.
According to the research team, the findings highlight the need for further education and strategies to ensure clinicians are administering the MMR vaccine to pediatric travelers.
“We would encourage additional research into better understanding why clinicians didn’t recognize that travelers were eligible for MMR vaccination as per ACIP guidelines and why they didn’t recommend it when they did note eligibility,” the study’s lead author Dr. Emily Hyle, an investigator in the division of infectious diseases at MGH, told Healthline. “Additional education around risks of international travel for measles exposure is likely essential, as well as the benefits and risks of MMR vaccination for children who are traveling internationally, in particular.”
Measles is incredibly contagious — even being in the same room as someone who has measles is enough to make you sick.
Those who aren’t immune have a 90 percent chance of becoming infected.
The risk of severe illness and life-threatening complications is greatest amongst young children.
“One in 5 infected children are hospitalized. Many of those will have life-threatening complications like pneumonia. One in a thousand will suffer encephalitis, often with permanent brain injury. And of children who contract measles, 1 to 3 per thousand will die,” says Dr. Michael Grosso, the chief medical officer and acting chair of pediatrics at Northwell Health’s Huntington Hospital.
All of this is very preventable through the safe and effective MMR vaccine.
Infants typically aren’t given the first MMR dose until 12 to 15 monthsTrusted Source and the second until they’re around 4 to 6 years old, since measles exposure is so rare in the United States.
The vaccine is less effective when given to children under 12 months — one dose is 93 percent effective in those who wait compared to 85 percent effective in those who get it early.
That said, pediatric international travelers are considered a vulnerable, at-risk group, and the ACIP recommends vaccinating children early to boost their chances of avoiding the virus while traveling abroad.
Though measles has been eliminated in the United States for almost 20 years, other countries continue to battle the virus. Between 2001 and 2016, about 30 percent of imported measles cases came from Europe, according to Hyle.
“Because there is more measles virus circulating outside of the U.S., the risk to U.S. pediatric travelers of becoming infected with measles while abroad is much higher than within the U.S.,” Hyle said.
“The risk of being infected with measles is much higher outside of the U.S., so it is recommended that children older than 1 year have had 2 MMR vaccinations and that children 6 to 12 months receive 1 MMR vaccination prior to travel,” Hyle added.
It’s unclear why so many clinicians aren’t administering the MMR vaccine to eligible patients prior to international air travel.
Grosso suspects it may come down in part how doctors relate to vaccine-hesitant parents.
“Right or wrong, if the physician knows the parents have always refused MMR vaccine until now, they’re very likely to refuse again,” Grosso said, noting that this leads to missed opportunities to recommend important vaccines.
Additionally, some clinicians — even those who specialize in travel vaccines — may not be aware that infants who will soon be traveling internationally should be getting the MMR vaccine.
“This is the knowledge gap, pediatricians may fail to recognize the child’s eligibility to receive the MMR vaccine prior to 12 months of age,” says Dr. David Fagan, the vice-chair of pediatrics at Cohen Children’s Medical Center.
Looking forward, the researchers hope to see stricter clinical adherence to the ACIP’s MMR vaccination guidelines.
Primary care physicians should not only discuss the need for pre-travel MMR vaccines during pre-travel consultations but during routine visits as well.
New research found that even though most infants and preschool-age children were eligible for MMR vaccination before traveling, only 40 percent had been properly vaccinated prior to their departure. Most eligible pediatric travelers weren’t vaccinated due to guardian refusal or a clinician decision.
Given the surge in measles cases worldwide and especially high risk for young travelers, researchers hope to improve how clinicians discuss and administer measles vaccines to pediatric travelers and their guardians.