FAQs • Snohomish County Health Department, WA • CivicEngage

If someone has received only one MMR vaccine, but they have serology/bloodwork showing immunity, do they still need the second dose?: If someone provides paperwork signed by a licensed healthcare provider that says their serology/bloodwork shows immunity, a second immunization is not needed.

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Measles

1. Are people born before 1957 still considered immune to measles?: Yes, people born before 1957 are considered immune to measles, and providing documentation of a date of birth earlier than 1957 is sufficient proof of immunity for employees who are not medical providers. However, any medical provider - including school nurses - must have two MMR vaccines, regardless of birth date. A date of birth before 1957 will not be enough to avoid exclusion for medical providers if there is a measles exposure at their location.

2. Is one dose of MMR enough for students and staff to continue going to/working at school during the exclusion period after a measles exposure?: No. Based on recent changes in guidelines from the Centers for Disease Control and Prevention and the Washington State Department of Health, students and staff must have both doses of the MMR vaccine.

3. If someone has received only one MMR vaccine, but they have serology/bloodwork showing immunity, do they still need the second dose?: If someone provides paperwork signed by a licensed healthcare provider that says their serology/bloodwork shows immunity, a second immunization is not needed.

4. Would a recent immunization throw off a titer (bloodwork to show immunity)?: The MMR takes up to two weeks to be effective, so if someone received the MMR vaccine and did a titer within two weeks, the titer may not show full immunity.

5. If I work at a site where there was a measles exposure, why can't I just go and get both doses of the MMR and return to work?: The MMR can take up to two weeks to be fully effective. In addition, if there is a reaction to the MMR vaccine, it can be harder to determine if symptoms are from the vaccine or from the measles virus.

6. If a school staff member who is not fully immunized visited or substituted at a school during a measles exposure, are they excluded from all school buildings for the exclusion period?: Yes. Unimmunized or under-immunized staff members or substitutes that visited a school during an exposure window must be excluded from any school until after the exclusion window. However, staff at other school buildings where the under-immunized worker spent time do not need to be excluded unless a case occurs at their school.

7. I was fully vaccinated between 1963 and 1968, but my blood test does not show immunity to measles. Do I need two doses?: One dose is sufficient. However, if there has been an exclusion at your workplace (a school or medical practice), you will be excluded for the duration. Keep documentation of all vaccinations and bloodwork to show immunity in the future.