The Delaware Division of Public Health (DPH) is sending this health advisory to advise clinicians and health care partners of the need to ensure Delaware children and those traveling internationally, or to parts of the country where measles is currently circulating, are up to date on their Measles Mumps Rubella (MMR) vaccinations.

Summary

With measles cases rising in the U.S., primarily driven by a large Texas/New Mexico outbreak, MMR vaccines are the best preventative against the virus. The Centers for Disease Control and Prevention’s (CDC) immunization schedule currently recommends routine vaccination with a two-dose series of the MMR vaccine — the first dose at 12 to 15 months of age, and the second dose at 4 to 6 years of age. Additionally, there are special vaccination recommendations for travelers and for those who did not receive their vaccination within the recommended timeframes.

Special Recommendation for Travelers

Individuals 6 months and older who are planning to travel internationally or to areas in the U.S. where measles is spreading (such as Texas and New Mexico), and who are not known to have been fully vaccinated against measles should receive an MMR vaccine, preferably
two weeks before travel. Infants ages 6 to 11 months who receive one dose of MMR vaccine pre-travel will need two more doses of MMR vaccine later in life, the first of which should be administered when the child is 12 to 15 months old and the second at least 28 days later.
Individuals 12 months or older (including children, teens, and adults) who will be traveling and who do not have documented evidence of measles immunity, should receive two doses of MMR vaccine separated by at least 28 days. This includes individuals traveling to any international destination or to areas of the U.S. where measles is spreading. See this link for what qualifies for evidence of immunity to measles. Note that verbal history of vaccination or measles disease does not constitute evidence of immunity. If an eligible patient will be traveling and there is doubt about whether or not they had previously received two doses of measles containing vaccine, such patients should be encouraged (through a shared decision-making process) to receive a dose to minimize the risk of acquiring the disease. The MMR vaccine is safe and well tolerated and the benefits in this situation favor providing the vaccine.

Background

The CDC has noted a significant increase in measles cases across the country. Measles is a highly contagious viral illness and can cause severe health complications, including pneumonia, encephalitis (inflammation of the brain), and death, especially in unvaccinated persons. Additionally, even after recovering from initial infection, severe neurologic complications of measles have been known to occur up to a decade after the initial illness. Measles typically begins with a prodrome of fever, cough, coryza (runny nose), and conjunctivitis (pink eye), two to four days before rash onset. The incubation period for measles from exposure to fever is usually about 10 days (range seven to 12 days), while rash onset is typically visible around 14 days (range seven to 21 days) after initial exposure. The virus is transmitted through direct contact with infectious droplets or by airborne spread when an infected person breathes, coughs, or sneezes, and can remain infectious in the air and on surfaces for up to two hours after an infected person leaves an area. Individuals infected with measles are contagious from four days before the rash starts to four days afterward.

As of March 14, 2025, the CDC reports a total of 301 measles cases have been reported by 15 U.S. jurisdictions in 2025, including Pennsylvania, Maryland, and New Jersey. Of these cases, 259 are related to the Texas/New Mexico outbreak. Most of the cases are among
individuals who are either unvaccinated or their vaccination status is unknown. Measles was declared eliminated from the U.S. in 2000; however, measles cases are commonly brought into the country by travelers who are infected while in other countries.
Measles is almost entirely preventable through vaccination. MMR vaccines are safe and highly effective, with one dose being 93% effective and two doses being 97% effective against measles.

Recommendations for persons with no planned travel

• Schools, early childhood education providers, and health care providers should work to ensure students are current with MMR vaccine.
  • Children who are not traveling internationally should receive their first dose of MMR at age 12 to 15 months and their second dose at 4 to 6 years. See above for recommendations for travelers.
• In addition, providers should encourage all children over 12 months, adolescents and adults who are not up to date on their MMR vaccination and do not have evidence of measles immunity to receive MMR vaccination to bring them up to date as long as they do not have contraindications to vaccination. At least one of the following is considered evidence of measles immunity:
    1. Birth before 1957
    2. Documented administration of two doses of live measles virus vaccine (MMR, MMRV, or other measles-containing vaccine)

Laboratory (serologic) proof of immunity or laboratory confirmation of disease.

Actions to take when you suspect measles

• Providers should have a high index of suspicion and consider measles on the differential diagnoses in anyone with fever (≥101°F or 38.3°C) and a generalized maculopapular rash with cough, coryza, or conjunctivitis particularly if they have recently travelled internationally or to Texas, New Mexico or other areas in the U.S. where measles is spreadin
  • Isolate: Do not allow patients with suspected measles to remain in the waiting room or other common areas of a health care facility; isolate patients with suspected measles immediately, ideally in a single-patient airborne infection isolation room (AIIR) if available, or in a private room with a closed door until an AIIR is available. Health care providers should be adequately protected against measles and should adhere to standard and airborne precautions when evaluating suspect cases, regardless of their vaccination status. Health care providers without evidence of immunity should be excluded from work from day five after the first exposure until day 21 following their last exposure. Where possible, offer testing outside of facilities to avoid transmission in health care settings. Call ahead to ensure immediate isolation for patients referred to hospitals for a higher level of care.
  • Notify: Immediately notify DPH about any suspected case of measles to ensure rapid testing and investigation (see contact below).
  • Test: Follow CDC’s testing recommendations and collect either a nasopharyngeal swab, throat swab, and/or urine for reverse transcription polymerase chain reaction (RT-PCR) and a blood specimen for serology from all patients with clinical features compatible with measles. RT-PCR is available at the DPH Laboratory as well as from commercial laboratories
  • Provide Post-Exposure Prophylaxis: Close contacts of measles cases who do not have evidence of measles immunity should be provided with post-exposure prophylaxis as soon as possible. This is done by providing MMR within 72 hours of exposure to those without contraindications, or immunoglobulin (within six days) to those for who MMR is not a good option either because of contraindications to MMR or because more than 72 hours has passed. . If an eligible patient is seen within 72 hours and there is doubt as to whether or not they had previously received two doses of measles containing vaccine, such patients should be encouraged (through a shared decision-making process) to receive a dose to ensure they are protected and avoid the need for immunoglobulin. The MMR vaccine is safe and well tolerated and the benefits in this situation favor of providing the vaccine.

Reporting

Measles is a reportable disease in Delaware. It is imperative that measles cases are reported in a timely manner because of the need for time-sensitive administration of post-exposure prophylaxis (PEP) to those exposed. All confirmed and suspected measles cases should be reported to the DPH Office of Infectious Disease Epidemiology at 302-744-4990 (Monday to Friday, 8:00 a.m. to 4:30 p.m.), 1-888-295- 5156 (24/7) or by email at reportdisease@delaware.gov.

Additional Information

• Child and Adolescent Immunization Schedule by Age