CHICAGO — With the measles spreading in the largest outbreak in years, are you protected?
Even those who got a vaccine, if you are a certain age, you may need another shot.
And some never got a vaccine at all.
Many adults assume they got the measles vaccine. But it was only introduced in 1963. But surprisingly, people born before then may be safe.
Dr. Allison Bartlett is a pediatric infectious disease specialist at the University of Chicago Medicine.
“We assume anyone born before 1957 was exposed to several outbreaks of measles so they have immunity,” she said. “It turns out about 98% of people who were born before 1957 are immune. That’s how common measles was. Everyone got it so they are in the clear.”
If they survived the measles outbreaks of the ‘50s, people developed immunity that lasts a lifetime. But those who got vaccinated after that may still be in jeopardy.
Two versions of the measles vaccine were available between 1963 and 1967, a live and a killed version. The killed virus vaccine turned out to be not as effective. People who have their medical records can check to see which one they got. Without the knowledge, they can get a blood test to check for immunity. But Bartlett says it may be easier to just consider anther vaccine.
“There’s no harm in giving it if you’ve already gotten it,” she said.
Recognizing the opportunities to increase protection among the community at large so people who aren’t vaccinated people in these particular birth cohorts who may not have gotten the best product that is currently available is important so we can protect the vulnerable infants.
- Born before 1957 – 98% are immune to measles
- Born 1957-1963 – need measles vaccine
- Born 1963-1967 – may need revaccination
- Born after 1967 – immune to measles if vaccinated
Anyone born before 1957 shouldn’t worry.
From 1957 to 1963, people who were born, were not exposed to measles and not vaccinated at the recommended age. They need a vaccine dose.
Anyone born from 1963 to 1967 was likely vaccinated but perhaps with a faulty inoculation. Experts advise to revaccinate.
After 1967 the ineffective vaccine was pulled and the Measles Mumps Rubella vaccine people received is still protecting them.
As for children, most infants are vaccinated at a year old, and then again between the ages of 4 and 6, the vaccine will provide lifetime immunity from the measles.