Is the measles outbreak that occurred in Disney Land of a different strain than what’s in the vaccine?

Here is a question I got recently that I want to publicly respond to:

Is the measles outbreak that occurred in Disney Land of a different strain than what’s in the vaccine? Are those who are vaccinated not protected?

The measles virus has many different genotypes, but only one serotype. When you say, “different strain,” that means different variation in genotype.

The virus can vary a bit genetically, but they all “look” the same when it comes to our immune systems. When a virus is all of the same serotype, they have the same antigens (proteins that our bodies recognize and make an immune response to) on the outside.

It shouldn’t matter of what genotype the measles virus is (and they do vary), they all will be recognized by a vaccinated body’s immune system in the same way.

If you’re vaccinated, your body WILL recognize any strain/genetic variant of measles. And we confirm that with how very effective our measles vaccine is.




And as a note, it’s pretty cool that there are different genetic variations of this virus because it allows researchers to track different outbreaks and help figure out where an outbreak originated. Sometimes different outbreaks are of different origin, and that helps determine if outbreaks in different places are from the same source, or from a completely different source.

These two photos posted by Vaccine Nation from the CDC may help demonstrate this concept:

Screen Shot 2015-02-23 at 2.04.05 PM Screen Shot 2015-02-23 at 2.04.21 PM