As confirmed measles cases surge in the United States, pediatricians are being confronted with a highly infectious, vaccine-preventable disease that can have long-lasting effects on children who become infected.
Due to a highly effective vaccine and the United States having achieved elimination status in 2000, many pediatricians may be unfamiliar with measles.
Authors of “What’s Old Is New Again: Measles,” published today in Pediatrics, provide an update on measles presentation, clinical course and outcomes.
“Thanks to widespread use of the measles vaccine, this disease had become rare in the United States, and many pediatricians have never seen a case,” said Caitlin N. Li, M.D., M.H.Q.S., FAAP, a lead author of the article. “Unfortunately, measles is resurging in the setting of declining vaccination rates. We hope this article supports pediatricians in counseling families about the importance of vaccination and helps them promptly recognize and care for patients with measles.”
Cases climbing, vaccine coverage dropping
As of April 3, 607 cases of measles have been confirmed in 21 states, according to the Centers for Disease Control and Prevention. The total likely is an undercount as it may represent only those ill enough to seek medical care.
Measles is one of the most contagious viruses in the world. The measles-mumps-rubella (MMR) vaccine remains the best way to prevent illness. Two doses of MMR are 97% effective.
However, MMR vaccine coverage continues to decline. Globally, only 83% of children had received a first dose of MMR vaccine in 2023, and only 92.7% of U.S. kindergartners had received two doses of MMR vaccine in the 2023-’24 school year, authors wrote. Because of its high infectivity, over 95% of people in a community must be immune to prevent widespread transmission.
An informal poll of practicing pediatricians and practice managers show many providers are seeing a wide range of responses from families in the weeks after the measles outbreak began. Concerns and responses included seeing increased vaccine hesitancy among families and distrust in vaccinations to those seeking earlier immunizations for their children and asking if vaccines will continue to be available in the future.
The estimated number of measles cases worldwide increased 20% between 2022 and 2023. In the U.S., four outbreaks were reported in 2023 and 16 in 2024. In 2024, 40% of those with confirmed measles were hospitalized, including 52% of children under 5 years and 25% of those 5-19 years, authors wrote. While vaccination is one of the greatest successes of public health, vaccine refusal has played a large role in resurgence of measles.
Responding to outbreaks
To prepare for a measles outbreak, clinicians should review materials distributed by their clinical site or local health department. Staff should familiarize themselves with the clinical presentation of measles.
Providers should become familiar with their site’s immediate infection prevention processes for patients with confirmed or suspected measles, including whether and where the site has airborne infection isolation rooms (AIIRs).
If measles is suspected, avoid sending patients to the emergency department unless they may require hospitalization or as instructed by local public health authorities. Providers should wear an N95 respirator or equivalent protection when evaluating a patient for measles. Patients with measles should be isolated, ideally in AIIRs. If an AIIR is not available, place patients in a private room with a closed door. Do not use the room for at least two hours after the patient leaves the room.
Providers should refer to the AAP Red Book for recommendations for use of immunoglobulin and MMR vaccine based on specific clinical scenarios. Routine MMR vaccination (first dose at 12-15 months of age and second dose at 4-6 years of age) is recommended.
In cases of an outbreak or pending travel to an area of high infection, pediatricians may consider early vaccination:
- Administer MMR vaccine to infants ages 6-11 months at least two weeks before planned international travel.
- Administer MMR vaccine to infants ages 6-11 months during outbreaks, if advised by local public health authorities.
- Infants who receive their first dose of MMR vaccine at less than 12 months of age should receive two doses after 12 months of age for adequate lifetime immunity.
- Combined measles-mumps-rubella-varicella vaccine should not be administered to those less than 12 months.
Pediatricians also should refine vaccine counseling strategies, be prepared to counter misinformation and identify public health advocacy opportunities at the local, state and/or national levels.
Resources
- AAP Red Book chapter on measles
- Measles FAQs
- AAP Fact Checked articles on measles vaccine safety and effectiveness and how vitamin A does not prevent measles
- Information for families from HealthyChildren.org on how to protect children during a measles outbreak
- FAQs on how to protect babies from a measles outbreak from HealthyChildren.org
