WCAAP Vax Corner May 2024 – Measles Outbreak

Frank Bell, MD, FAAP, Vaccine Committee Co-Chair

Would you recognize measles?

Who would you call if you were concerned about measles in your clinic?

Although measles was declared officially ‘eliminated’ in the US in the year 2000, cases of measles have continued to occur and to spread every year since that date, and 2024 is no exception. By the end of April the CDC had announced a total of 128 cases for the year, involving 20 jurisdictions including Washington state, noting that this number is already greater than the total number of cases reported in 2023. Measles is highly-transmissible and a threat to children who are unimmunized or unprotected by immunization, including those who are immune-compromised.

Measles virus is one of the most infectious agents known to man – of every 10 susceptible people exposed to an individual with measles, 9 are likely to become infected. Measles can be transmitted to healthcare workers and to patients for up to 2 hours after an infected child has left the exam room. Fortunately, measles is eminently preventable: measles vaccine is safe and highly-effective in reducing the risks of infection and of feared complications.

The current national outbreak offers a reminder to make sure that families are up-to-date with recommendations for measles immunization. Routine advice since 1989 has included the recommendation for 2 doses of measles vaccine for all children & teens and for those in post-secondary education including college and vocational training programs. The CDC estimates that a single dose of MMR vaccine is estimated to be 93% effective against measles, a second dose raises this figure to 97%. The AAP Red Book notes that the second dose provides protection to those who failed to respond to the primary measles immunization and therefore is not a booster dose.

From a Public Health perspective, this second dose is important and has helped to control recent outbreaks and was crucial in obtaining current elimination status for the US. The drop-off in immunization rates associated with the COVID-19 pandemic shutdown (and increasing international travel associated with reopening) place this status at risk. Communities are in danger of measles transmission where immunization rates fall below 95%. Reminding families to keep up-to-date with all recommended vaccines is important to keep our communities safe, and the current surge in US measles cases provides a reminder to make sure that everyone is up-to-date – Adults, teens and children included.

The AAP & CDC’s Project Firstline provide important advice: https://downloads.aap.org/AAP/PDF/ThinkMeasles-final.pdf

Leave a Reply

Your email address will not be published. Required fields are marked *