We are on our way to a record breaking measles season. Go to the USA!
Since the disease was essentially eliminated from the country in 2000, there have been a few outbreaks of traveler-triggered outbreaks each year. As the number of cases is over 600 this year, you may be wondering: Can I trust my childhood measles vaccine? Did I even get my measles vaccine from my childhood?
Children should receive a shot of measles vaccine (supplied as MMR or measles mumps rubella vaccine) shortly after they turn one year old. The immune system of some children is not fully prepared at this age ̵
Why might it be that your vaccine is old is not good enough
The measles vaccine first became available in 1963, and for a few years there were two different vaccines. The live, weakened measles virus version is still in use today. Another shot of killed virus was introduced at about the same time, but discontinued in 1967 because it was not as effective.
If you received the less effective vaccine, it is recommended that you receive a second dose, this time with the live vaccine. (It is possible that you shot again as a child.)
In 1989, the CDC began recommending that even children who had received the regular vaccine should get a second shot because it does not work for all the first time. One dose is 93% effective; Efficacy increases to 97% for both doses.
How to Know If You Need a New Injection
As mentioned, you can always check your vaccination records (if you can find them) and, if in doubt, ask your doctor for advice. In most cases, they recommend the same thing the CDC says, to make sure you have at least one dose of the live vaccine, and in some cases recommend two. Here is the collapse of the CDC:
They do not need a vaccine if they …
- They know that they had measles
- They were born before 1957 (at that time ) All got measles)
- You had a lab test showing that you are immune to measles
If you know you had a measles / MMR vaccine on schedule, that's fine. ..
- You are a preschooler (because you are receiving the second dose at baseline)
- You are a adult and have a low risk of being exposed to measles
You should receive a second dose if:
- You are a child of school age
- You are an adult traveling, working in healthcare, attending college, or otherwise at high risk of being exposed to measles  If you do not know your status, get the shot anyway. The CDC states that "it does not hurt to receive another dose of MMR, even if you are already immune to measles."
The above advice applies to almost everyone, but there are some people who should not get the shot. If you are pregnant or if you or a family member has a weakened immune system due to immune deficiency or chemotherapy, the vaccine carries risks that may outweigh the benefits. (For the full list of contraindications for the CDC, see here.) However, do not assume that you discuss the risks with your doctor to find out what is right for you.