In the JournalsPerspective

Just 41% of eligible kids get MMR vaccine before travel outside US

Emily P. Hyle, MD, MSc
Emily P. Hyle

Just 41% of eligible children received the MMR vaccine during pretravel consultation before traveling outside the United States during a recent 10-year period, mainly due to guardian refusal or clinician decision, according to study results published in JAMA Pediatrics.

“Children who travel internationally without measles immunity are at increased risk for being infected with measles, which can cause severe and even life-threatening illness, especially for very young children,” Emily P. Hyle, MD, MSc, of Massachusetts General Hospital’s division of infectious diseases, told Healio. “Imported measles cases also can provoke further outbreaks of measles within the United States, putting others at risk as well.”

Hyle and colleagues performed a cross-sectional study of 14,602 pretravel consultations for international pediatric travelers at 29 sites associated with Global TravEpiNet (GTEN) between Jan. 1, 2009, and Dec. 31, 2018. The analysis included 2,864 MMR vaccine-eligible children aged between 6 months and 18 years, of which 1,475 were boys, 1,389 were girls, 365 were infants aged 6 to 12 months, 2,161 were preschoolers aged 1 to 6 years and 338 were school-aged children aged 6 to 18 years.

Of the travelers, 1,182 (41.3%) received the MMR vaccine. The unvaccinated group included 161 (44.1%) eligible infants, 1,222 (56.5%) eligible preschoolers and 299 (88.5%) eligible school-aged children. The most common reasons cited for nonvaccination among the group were guardian refusal (36.4%) and clinician decision (36.9%).

Photo of young boy with measles rash 
Only 41% of pediatric travelers were given the measles, mumps and rubella vaccine during pretravel consultation, mainly due to guardian refusal or clinician decision.
Source: Adobe Stock

“We had expected some guardians to refuse MMR vaccination when offered, but we were very surprised and concerned that clinicians were often not recommending it,” Hyle said. “These data are so helpful because they suggest that we could potentially improve MMR vaccination and reduce measles cases among international travelers by better educating clinicians, travelers and their families.”

Vaccination-eligible travelers were found to be less likely to be vaccinated at pretravel consultation if they were school-aged (OR = 0.32; 95% CI, 0.24-0.42). Travelers evaluated at specific GTEN sites also were found to be less likely to receive the vaccination (South OR = 0.06; 95% CI, 0.01-0.52; and West OR = 0.1; 95% CI, 0.02-0.47).

According to a recent MMWR, there was a 167% increase in global measles cases from 2016 to 2018, with high rates of mortality from the disease occurring in children aged younger than 5 years. Large outbreaks in the Democratic Republic of the Congo and Samoa have killed mostly young children.

A large outbreak of measles in New York City that sickened more than 600 people and lasted almost a year before it was declared over in September was linked to an unvaccinated child who acquired measles on a trip to Israel.

In the U.S., the CDC recommends that children receive a first dose of MMR vaccine at age 12 to 15 months, and a second dose between age 4 and 6 years.

“However,” Hyle said, “recommendations are different for children who are traveling internationally,” where the risk for contracting measles is much higher. Children traveling outside the U.S. should have received two doses if they are older than age 1 year, and one dose if they are 6 to 12 months old, Hyle said.

“Our findings for both adult and pediatric international travelers emphasize that providers and travelers need to better understand the risks of measles exposure during international travel and the benefits of MMR vaccination,” she said. “Further education to providers regarding risks of measles exposure during international travel and benefits of MMR vaccination are definitely needed.”– by Eamon Dreisbach

Disclosures: Hyle reports receiving grants from the NIH during the conduct of this study. Please see the study for all other authors’ relevant financial disclosures.

Emily P. Hyle, MD, MSc
Emily P. Hyle

Just 41% of eligible children received the MMR vaccine during pretravel consultation before traveling outside the United States during a recent 10-year period, mainly due to guardian refusal or clinician decision, according to study results published in JAMA Pediatrics.

“Children who travel internationally without measles immunity are at increased risk for being infected with measles, which can cause severe and even life-threatening illness, especially for very young children,” Emily P. Hyle, MD, MSc, of Massachusetts General Hospital’s division of infectious diseases, told Healio. “Imported measles cases also can provoke further outbreaks of measles within the United States, putting others at risk as well.”

Hyle and colleagues performed a cross-sectional study of 14,602 pretravel consultations for international pediatric travelers at 29 sites associated with Global TravEpiNet (GTEN) between Jan. 1, 2009, and Dec. 31, 2018. The analysis included 2,864 MMR vaccine-eligible children aged between 6 months and 18 years, of which 1,475 were boys, 1,389 were girls, 365 were infants aged 6 to 12 months, 2,161 were preschoolers aged 1 to 6 years and 338 were school-aged children aged 6 to 18 years.

Of the travelers, 1,182 (41.3%) received the MMR vaccine. The unvaccinated group included 161 (44.1%) eligible infants, 1,222 (56.5%) eligible preschoolers and 299 (88.5%) eligible school-aged children. The most common reasons cited for nonvaccination among the group were guardian refusal (36.4%) and clinician decision (36.9%).

Photo of young boy with measles rash 
Only 41% of pediatric travelers were given the measles, mumps and rubella vaccine during pretravel consultation, mainly due to guardian refusal or clinician decision.
Source: Adobe Stock

“We had expected some guardians to refuse MMR vaccination when offered, but we were very surprised and concerned that clinicians were often not recommending it,” Hyle said. “These data are so helpful because they suggest that we could potentially improve MMR vaccination and reduce measles cases among international travelers by better educating clinicians, travelers and their families.”

Vaccination-eligible travelers were found to be less likely to be vaccinated at pretravel consultation if they were school-aged (OR = 0.32; 95% CI, 0.24-0.42). Travelers evaluated at specific GTEN sites also were found to be less likely to receive the vaccination (South OR = 0.06; 95% CI, 0.01-0.52; and West OR = 0.1; 95% CI, 0.02-0.47).

According to a recent MMWR, there was a 167% increase in global measles cases from 2016 to 2018, with high rates of mortality from the disease occurring in children aged younger than 5 years. Large outbreaks in the Democratic Republic of the Congo and Samoa have killed mostly young children.

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A large outbreak of measles in New York City that sickened more than 600 people and lasted almost a year before it was declared over in September was linked to an unvaccinated child who acquired measles on a trip to Israel.

In the U.S., the CDC recommends that children receive a first dose of MMR vaccine at age 12 to 15 months, and a second dose between age 4 and 6 years.

“However,” Hyle said, “recommendations are different for children who are traveling internationally,” where the risk for contracting measles is much higher. Children traveling outside the U.S. should have received two doses if they are older than age 1 year, and one dose if they are 6 to 12 months old, Hyle said.

“Our findings for both adult and pediatric international travelers emphasize that providers and travelers need to better understand the risks of measles exposure during international travel and the benefits of MMR vaccination,” she said. “Further education to providers regarding risks of measles exposure during international travel and benefits of MMR vaccination are definitely needed.”– by Eamon Dreisbach

Disclosures: Hyle reports receiving grants from the NIH during the conduct of this study. Please see the study for all other authors’ relevant financial disclosures.

    Perspective
    Aaron E. Glatt

    Aaron E. Glatt

    This study demonstrated that there are many people who are identified as being at risk and — for unclear reasons — aren't getting vaccinated appropriately when they travel.

    It's not only traveling to an endemic area — the same rules apply when the endemic area comes to you. If there's an outbreak in your area, you should view yourself as traveling to an endemic area, with the same guidelines. It's the same from my perspective, whether you're traveling to the endemic area, or the endemic area has come to you. It is the same reason to move up the vaccination schedules and to get appropriately vaccinated if you're already at the time for the schedule and have not yet done so.

    I think some clinicians may not be fully up to date about travel guidelines and/or may have their office set up in a certain way that the child gets called in based upon the standard guidelines. In specific circumstances, however, I think the standard guidelines need to be updated. There are a lot of new data out there that demonstrate that the old guidelines aren't necessarily optimal in specific situations, such as endemics.

    Certainly, in a situation where there is an outbreak in your area, or if you're traveling to an outbreak area, you should follow the updated guidelines for travel. For measles, those updated travel guidelines should become the standard guidelines if there is measles in your area. I believe pediatricians should follow the updated travel guidelines and recommendations rather than using the standard official CDC guidelines, which are really not applicable if there's an epidemic in your area.

    The most common question I've gotten from people just calling up asking me about measles travel is, “Can we travel to this area?” My answer in general is that it’s safe to travel if you have been vaccinated, but you should make yourself as resistant to diseases as you can. There are other guidelines, besides measles guidelines, that you should take into account.

    You should make sure you are appropriately fully vaccinated for travel to a specific region of the world, and you should do this far enough in advance of the travel that you will get the full benefit from vaccination.

    If you vaccinate the day you're traveling, or very close to it, which is sometimes what happens, it is not optimal. For measles, you should vaccinate at least 2 weeks before you travel to get the maximum benefit. If you're going to need two doses, you should do it at least 6-8 weeks beforehand so you can get the full benefit.

    • Aaron E. Glatt, MD
    • Spokesperson, Infectious Diseases Society of America
      Chair of medicine and chief of infectious diseases
      Mount Sinai South Nassau
      Oceanside, New York

    Disclosures: Glatt reports no relevant financial disclosures.