Giving MMR Vaccine Early To Protect Children Against Measles
As the number of measles cases tied to the Disneyland outbreak continues to rise, parents are growing concerned about possible measles exposure in children who are not yet old enough to receive their first dose of MMR (measles, mumps rubella) vaccine. The CDC recommendation is to administer the first dose of MMR between the ages of 12-15 months. However, this recommendation leaves children under one year of age at risk, and so Abigail, like many other parents with young children, raised her concerns on our Vaccinate Your Baby Facebook page by asking
Does anyone have information on giving the MMR vaccine early? My child is just 6 months old. We live in Southern California, a hotbed of the latest measles outbreak. We’re right in it…even our local grocery store was exposed.
I’m a stay at home mom and he has no siblings, and at this point, we are not taking him to public areas often. But this outbreak is incredibly worrisome. I read that children who travel can be offered the MMR vaccine at 6 months. At what point should we consider it for our child? Any studies on early vaccination — risks, effectiveness, etc?
Every Child By Two Scientific Advisory Board Member, Mary Beth Koslap-Petraco, DNP, PNP-BC, CPNP, FAANP responds to Abigail’s question as follows:
MMR vaccine is very safe for babies. I have given it numerous times to children less than 12 months old who are traveling outside the U.S. The reason we usually don’t administer the vaccine until babies are 12 months old is because there is evidence that the baby still has some passive immunity from the mom. This can prevent the baby from mounting a robust immune response to the vaccine. Once the baby is 6 months old that immune response does start to wane. So for babies traveling outside the country we don’t like to take any chances. Especially since measles is endemic in many places outside of the U.S., to include countries in Europe, Asia, the Pacific, and Africa. In fact, of the 288 cases of measles that occurred in the U.S. during the first half of 2014, 280 cases (97%) were associated with importations from at least 18 countries.
If you live or are traveling to an area that has a known measles outbreak, then it would definitely be advisable to talk to your child’s doctor about administering an MMR vaccine prior to 12 months of age. However, it is important to realize that those babies will need to get another MMR when they are 12 months old because by then we can be more certain that the passive immunity from the mother is gone.
Because studies have shown that about 5% of individuals don’t mount an immune response after one shot, we then give a second MMR at 4-6 years of age. Unfortunately, about 1% of the population will never develop immunity even after the recommended two shots. That is one reason we must make sure everyone who can be vaccinated is. This way we keep the possibility of disease transmission low, which in turn protects both the people who could not mount immunity through the vaccine, as well as those who can’t be vaccinated because they’re not old enough or have certain medical condition that prevent them from being vaccinated.
This is a concept we refer to as herd immunity and in the case of measles, which is highly contagious, we need as much as 94% of the population to be immune in order to maintain a threshold that will prevent outbreaks such as the one we’re seeing as a result of exposure in Disneyland. All it takes is for a single case of measles to arrive in this country to spark an outbreak. In the past, this has typically occurred as a result of an unvaccinated American who traveled outside the country who then unknowingly returned home with a measles infection. And since measles is contagious for up to four days before symptoms appear, it’s likely that contagious individuals would be out in public places without even knowing they are infected.
It is understandable for parents to be concerned about measles outbreaks. Measles can be extremely dangerous, especially to young children. That is why I would suggest you contact your doctor or local health department to inquire about the possibility of giving your child the MMR vaccine if they are between 6-11 months of age. The health department should be our go-to resource for assessing the risk of disease in our local communities and for helping us determine if the MMR vaccine is appropriate for a specific population.