Health Alert: Verifying Measles Immunity Status & Interim Expedited MMR Guidelines

Health Alert: Jan. 20, 2026

This is a Provider Alert from Snohomish County Health Department regarding measles in Snohomish County.

Current Situation

The Snohomish County Health Department has confirmed five measles cases in local children who were exposed to a contagious family visiting from South Carolina (see “Background”), and recent previous health alert for more details. These cases amount to an outbreak – a sign the disease is now spreading locally.

Three of the children tested positive for the virus that causes measles on Wednesday, Jan. 14. They had experienced fever, cough and rashes consistent with measles. The additional two children are symptomatic (fever+rash) with a known epi-link to the previous cases. All five of the children were unvaccinated for protection against measles. 

Due to potential for exposure to measles in Snohomish County, there is an increased need to demonstrate immunity to measles in order to support return to work/return to school following an exposure as well as expedite the second dose of MMR as per new interim guidance from DOH.  

Actions Requested 

Be aware of possible measles exposures in King and Snohomish counties and consider actions to verify immunity status, particularly in adults that may not have electronic records of previous vaccine or illness. Be aware of new interim expedited MMR vaccination guidance from Washington State DOH. 

WA DOH Interim Expedited MMR Immunization Guidance

These recommendations apply only to people who live in or visit counties with active measles outbreaks. At this time, only Snohomish County meets this criterion. We may update these interim recommendations based on local epidemiology.

Updated age-based measles, mumps, and rubella (MMR) vaccine recommendations:

• 0 – 5 months: No MMR is recommended.
• 6 – 11 months: No MMR is recommended unless indicated for planned international travel or travel to an area outside Washington where public health recommends vaccination because of an active measles outbreak.
• 1 – 17 years: Receive the first dose of MMR or measles, mumps, rubella, and varicella (MMRV) as soon as possible. 
  • A second dose is recommended: 
    • 28 days later if the first dose was MMR, or
    • 3 months later if the first dose was MMRV.

Please review the Interim Pediatric Measles Outbreak Vaccination Recommendations [PDF] for more details. This guidance will also be posted on the DOH “You & Your Family” measles webpage. 

• Assess immunization status during healthcare visits at every visit and strongly recommend measles, mumps and rubella (MMR) vaccination based on the recommended schedule, health condition, occupation, and other risk factors such as travel.
• If you are reviewing your client’s immunization record in the state immunization registry (WAIIS), please note that the first section displayed is the ‘forecast,’ which will outline any due or overdue immunizations. The forecast section does not confirm that a vaccine has been given, only that one (or more) are due.
• Under-vaccinated individuals may be at risk for measles infection due to outbreaks that occur in the US or anywhere else in the world. 
• If you are treating pediatric patients 6-11 months old, please inquire about upcoming international travel, or potential travel to an area with a measles outbreak. If there is upcoming travel that could result in measles exposure, offer a single MMR single vaccine dose for protection in case of an exposure. The two standard doses of the MMR vaccine, starting at 12 months, will still be required.
• If you are running low on critical supplies, including doses of the MMR vaccine, and have exhausted all local options for additional supplies, you can contact the NWHRN duty officer (425.988.2897), who can help you fill out a resource request to the state or source mutual aid from other healthcare facilities.

Verifying Immunity

• If a patient is coming into clinic with unknown measles immune status:
  • And they are ill with symptoms concerning for possible measles: 
    • Mask immediately and isolate ASAP, ideally waiting outside of the clinic until they are able to be taken to a isolation room.
    • Once in isolation provide evaluation and treatment as appropriate
    • If they are requesting IgG titers for Measles in addition to eval for their symptoms this is fine to collect while symptomatic as long as done in appropriate isolation
  • And they are asymptomatic with:

• No known measles exposure: can treat normally

• Known measles exposure <72 hours prior: can treat as non-infectious for care, should provide MMR as per PEP Guidance (see page 25) in a normal clinic manner
• Known measles exposure 3-6 days prior: very unlikely to be infectious but could be possible, ideally seen for titer or other care outdoors or in isolation, but not necessary. May also qualify for Ig PEP depending on status 
• Known measles exposure 7 or more days prior: Should be treated as potentially infectious and seen in isolation or outdoors for titers or other care

Notify 

• Report suspected measles cases to the Snohomish County Health Department at (425) 339-3503 immediately AND before discharging or transferring patients.
• Public Health will ensure appropriate, rapid testing and investigation.

Background 

One adult and two children were infectious from Dec. 27, 2025, through Jan. 1, 2026, while visiting King and Snohomish counties on a trip from South Carolina. The parent reported having received at least one vaccine to protect against measles; the children were unvaccinated.

The family visited multiple locations in Marysville, Mukilteo and Everett while contagious – but before being diagnosed – with measles. They also traveled through Seattle-Tacoma International Airport and visited a car rental facility near the airport.

3 epi-linked cases were subsequently identified and lab confirmed on Jan. 14, 2026. All three were unvaccinated for measles resulting in additional exposures locations in Everett and Edmonds. 2 additional epi-linked cases were identified on Jan 20, 2026 in the same household as two of the three previous epi-linking cases with no additional exposure sites identified.  

If a person was at a listed location below, during the noted dates and times, and they are not immune to measles, the most likely time a person would become sick would be 7-14 days after the exposure with a range of 7-21 days.

Measles illness starts with a prodrome of fever, cough, coryza, and conjunctivitis (typically lasting 2-4 days) and then a generalized maculopapular rash that typically begins on the face/head then spreads to the neck, trunk and extremities. Increases in measles cases and outbreaks are occurring in every region of the world.  

CDC recommends all U.S. residents aged 6 months and older without evidence of immunity, who plan to travel internationally, get the MMR vaccine at least 2 weeks prior to departure. Infants 6 to 11 months of age who get the MMR vaccine before international travel should get an additional 2 doses of MMR according to the recommended schedule, after 1 year of age.  

For further guidance or to report a case, contact Snohomish County Health Department at:  

• (425) 339-3503
• shd-CDQuestions@co.snohomish.wa.us 

Resources 

• For Healthcare Providers
  • Measles One-Pager for Healthcare Providers – Project Firstline and AAP
  • Measles - For Healthcare Professionals– CDC
  • Measles Specimen Collection Instructions for RT-PCR – WA DOH
  • Measles Specimen Collection Instructions for Serology – WA DOH
  • Safety Information for Measles, Mumps, Rubella (MMR) Vaccines – CDC
  • Measles Assessment Checklist – WA DOH
• For Infection Preventionists
  • Interim Measles Infection Prevention Recommendations in Healthcare Settings – CDC
  • Measles Playbook – APIC Emerging Infectious Diseases Task Force
• For Laboratories
  • Public Health Laboratories Lab Test Menu – WA DOH
  • Measles Specimen Shipping Guide – WA DOH 
• For General Public and International Travelers
  • Measles Resources – PHSKC
  • Plan for Travel – Measles – CDC