Need Another Measles Vaccine?
We are approaching a record measles season. Go USA!
Since the disease was virtually eradicated in the country in 2000, several cases have been reported each year as a result of outbreaks caused by travelers. With the number of cases exceeding 600 this year, you may be wondering: Can I trust my childhood measles vaccine? Perhaps I am even getting my childhood measles vaccine?
Children should receive the measles vaccine (given as MMR or measles, mumps, and rubella vaccine) as soon as they turn one year old. Some kids’ immune systems will not be fully prepared by this age – in which case the vaccine will not work – so everyone should get a booster shot around the time they start kindergarten.
Why your old vaccine may not be effective enough
The measles vaccine first became available in 1963 and two different vaccines have existed for several years. The live attenuated measles virus version is still used today. Around the same time, another drug was introduced with the killed virus, but its production was discontinued in 1967 because it was not as effective.
If you have received a less effective vaccine, it is recommended that you receive a second dose, this time with a live vaccine. (You may have gotten that extra shot as a kid.)
In 1989, the CDC began recommending that even children who received the regular vaccine get a second shot because, remember, it doesn’t work for everyone the first time. One dose is 93% effective; with both doses, the efficacy reaches 97%.
How to know if you need a new shot
As we discussed earlier , 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 will recommend the same thing as the CDC, which is that you get at least one dose of the live vaccine, and in some cases they will recommend two. Here’s a breakdown of the CDC :
You don’t need a vaccine if …
- You know you’ve had measles
- You were born before 1957 ( everyone had measles then)
- You have had a laboratory test that shows you are immune to measles
If you know you have received one dose of measles / MMR vaccine on a schedule, that is enough if …
- You are a preschool child (because you will get your second dose around the time you start school)
- You are an adult with a low risk of contracting measles.
You should receive a second dose if:
- You are a school-age child
- You are an adult who travels, works in health care, goes to college, or is otherwise at high risk of contracting measles.
If you don’t know your status, take a picture anyway. The CDC states that “getting another dose of MMR will not harm you, even if you are already immune to measles.”
The above advice applies to almost everyone, but there are people who should not be vaccinated. If you are pregnant or if you or a family member has a weakened immune system due to an immune disorder or chemotherapy, the vaccine carries risks that may outweigh the benefits. ( A complete list of CDC contraindications is here .) Don’t assume, however – discuss the risks with your doctor to find out what’s right for you.