There is a measles outbreak unfolding in Washington. Unfortunately, there have been multiple outbreaks across the US in the past few months. Here’s info about outbreaks in 2018, as well.
The MMR vaccine is safe and effective. If you’ve hesitated or declined the vaccine in the past, please reconsider the science and risk to your child and their community now.
I haven’t written much about measles since 2015, but an outbreak in Washington State has prompted me to send out a few reminders. The first thing to know, which I know I already said, is that the MMR vaccine (protects children and adults against measles, mumps, and rubella) is safe & highly effective. If your children are immunized there is very little to worry about during a measles outbreak. The 1st dose (and 2nd dose for those infants and children who didn’t respond to the first) of the vaccine work to trigger lifelong immunity. Typically after the 1st dose (at 12 months old), 95% of people are protected for life. The 2nd dose (age 4) protects those not protected from the 1st dose and brings protection to 97-99%. If your child hasn’t had a 2nd dose of the MMR vaccine and you live where widespread measles infections are being reported, you can get the 2nd dose of MMR now as long as it’s been 1 month since the 1st dose. Call your pediatrician to inquire if you’re interested. The bottom line: immunized children can play and go to school and go to assemblies and even visit a clinic safely during an outbreak because the vaccine is so effective. Hurrah for science!
What To Know About Babies Too Young To Be Immunized For Measles(MMR):
I hate that I can’t completely say infants are perfectly safe during an outbreak. Infants are a vulnerable population during a measles outbreak. Measles is wildly contagious and during an outbreak, it can spread, especially to older infants who aren’t vaccinated yet. The good news is that risk of exposure outside of areas during an outbreak is low (more than 90% of us won’t get measles because we’re vaccinated so we also won’t spread it to your baby). Here’s an even more comprehensive post I wrote about this from 2015.
- For Babies Under 6 Months of Age: If a baby’s mother has had her MMR shots and/or had measles infection in her life she passed antibodies to her baby during fetal development while in-utero and continues to pass them passively while breastfeeding. Those antibodies provide protection for young infants and typically are thought to protect infants for up to 6 months or more. However, exactly how long for each baby is not ever known. Immunity wanes for these babies as they age and the mom’s antibodies fail to persist. The reason babies don’t get the MMR shot sooner than a year of age is because of the persistence of these maternal antibodies — if you put a vaccine in while maternal antibodies are still around the vaccine won’t stimulate the baby’s own immune system to respond, it will just get soaked up by the maternal antibodies doing their job.
- Okay To Go To The Grocery Or Have A Playdate With Your Infant? Yes! With a few caveats, of course. If you’re in a county where multiple cases of active measles have been recently reported (Clark County reporting 72 cases) you may take more caution disallowing strangers to hold your baby and/or steering clear of anyone with a cough. Measles is infectious on surfaces and in the air for 2 hours after an infected individual has been in the space so it’s tricky to provide solid guidelines of how to avoid it if it’s around. If ever ANY concern for exposure, call your pediatrician to discuss a visit. Like everything in life we balance risk with benefit and being out and about in the world. If planning on visiting with guests or sharing in on a playdate, why not ask parents to children involved, “Is everyone here immunized against measles that can be? If you or your family live in Vancouver, Washington area or Portland area, look at the clinics and multiple schools that have had exposures. I would recommend being clear about how you access a clinic with an infant in these counties during this outbreak.
- Is my child’s school protected against a measles outbreak? In many states, you can track vaccination status for your child’s school because exemptions (those opting out of immunizations for medical or philosophical reasons) are tracked. In Washington State, parents can check to see what percent of children are up to date on immunizations in kindergarten by searching SchoolDigger. Because vaccination status is tracked at the state level, many other states provide this service (some are up on School Digger). To find your data, start at school digger or try a search on the state’s Department of Health website for more. If you’ve run into a roadblock or can’t find the information, it’s always your right to request the numbers from school administration or the school nurse. Outbreaks like this are one of the reasons California discontinued allowing children to attend school without up-to-date immunizations. Their non-protection puts other children at risk.
- As a parent, do I need another MMR shot? What if I’m pregnant? It’s unlikely you need more MMR shots if you were born after 1957 when vaccination was universal, most of us all got the shot as children. In 1989 we also started to do a 2nd dose of MMR to get more people protected (closer to 100% of the population). Only adults working with vulnerable populations and in health care need to go and get 2nd dose now. If you have ZERO written documentation anywhere that you’ve had MMR shot, talk with your doctor. In addition, if you’re pregnant now, no MMR shot until after the baby’s born. You can get an MMR shot safely while breastfeeding.
- Traveling internationally with infants: If you’re planning to travel abroad with your infant and they are between 6-12 months of age, it’s recommended they get an MMR shot before travel to protect against measles. They’ll need to repeat that MMR dose at 1 year of age, and the last shot at age 4 years, but they will be better protected during travel to higher-risk areas while still an infant.
What To Know For Children During A Measles Outbreak:
- If your child is up-to-date on MMR vaccination they can play and go to school and live life as they normally would during an outbreak! The MMR vaccine provides lifelong immunity for almost all who get it.
- If your child has had the 1st dose of the vaccination (usually given at age 1) and they haven’t yet had their 2nd dose, if you want to get the 2nd dose before age 4 years, especially if you live in or near areas of widespread outbreak or you’re planning travel, call your pediatrician or family practice office. The MMR dosing interval is 28 days meaning you can get the 2nd dose at any age as long as it’s been 4 weeks since the first.
Washington State Outbreak Information January 2019:
As of March 13, 2019, Clark County reports 72 confirmed cases of measles in the state of Washington. 1 confirmed case now in King County. The 72 confirmed cases include two cases who traveled to Hawaii and another case who traveled to Bend, Ore.
- 1 to 10 years: 53 cases
- 11 to 18 years: 15 cases
- 19 to 29 years: one case
- 30 to 39 years: three cases
- Unverified: 7 cases
- Unimmunized: 63 cases — the data here is proof that it’s those without the vaccine that are most susceptible!
- 1 MMR vaccine: 2 cases
- In Clark County, 7.9% of children entering kindergarten had vaccine exemptions during the 2017-18 school year, according to the Washington State Department of Health. During the same school year, 7.5% of children in all grades in the county had vaccine exemptions. The county is working with teachers and families to ensure children at risk do not attend until they are immunized and/or this outbreak is under control.
- National vaccination rates per CDC.
- WA DOH Measles Update Site
- Measles Outbreaks – per CDC
- Measles Outbreak With A Baby At Home – SMD Blog 2015
- Cocooning For Measles – SMD Blog 2015
Regarding adult vaccination needs: I’m reading news online that if you were born between the years 1963 and 1967, or received the vaccine between those years, it might mean you need a second dose because they may have received an ineffective vaccine. https://www.healthline.com/health-news/some-adults-need-to-be-revaccinated-against-measles-021115#1
Alison Allen says
Thank you for re-posting this thorough article! I have a 6 month old (and 2.5 yo) and live in Seattle, and while I inquired with my pediatrician what his advice is, I appreciate knowing a bit more about the science and how to navigate. I appreciate all of your posts tremendously, and especially this one!
Jennifer Martin says
Also reminding people to have their titers checked can be good too. I had lost immunity to measles but didn’t know till I was pregnant with my first child and then had to wait till he was born to get a booster.
Cari Bader says
Can you please explain more about passively sharing antibodies through breastfeeding? If you breastfeed past age one, would the first mmr shot at age one be less effective?
Hello! Thank you for this article. It is very informative! Im curious about what your thoughts are related to air travel with an infant that is 1 week shy of 6 months during this outbreak? No confirmed cases in the departing or destination states. Doc not recommending MMR at this time due to the fact that there are no outbreaks in the visited states. Just curious if this was ever touched on during your research.
Unfortunately, measles antibody is not passed through breastmik for a relative period, neither in vaccinated moms, nor those immune through disease. Some measles antibodies are found in colostrum, but none past 2 weeks post partum
in your age breakdown- i’ve read that the king county case was a 51 year old man. And the MMR insert does say that caution should be used when administering the mmr to breastfeeding women.
Adam Price says
To [emphatically] echo Catherina’s comment: I have seen many sources say things like “Those antibodies … typically are thought to protect infants for up to 6 months or more.” (As in this article.) I cannot find any published studies that support that though. The one that Catherina provides indicates that only less than half of babies were still immune by 4 months, likely because “anti-measles IgA had dropped below the protective cut-off within the first 2 weeks of birth.” That study, from Nigeria, did not distinguish between mothers who had been vaccinated and those who were measles survivors.
Another study, from Belgium, did track the source of maternal immunity and found that at the 6-month mark, passive immunity transfer was present for only 1 child out of 87 whose mothers had immunity due to vaccination (and only 15% for the ‘naturally’ immune mother-baby pairs.)
Dr. Swanson – Do you have any other literature that demonstrates more promising findings regarding passive immunity transfer?
Thank you for posting this!! It makes me feel so much more comfortable for my little 8 month old. Interesting about breast milk immunity too!