We all know the saying, correlation equals causation, right?
So if you get an MMR vaccine and get the measles a week later, it has to be the vaccine, right?
Should I Blame the Vaccine If I’m Sick and I Just Got Vaccinated?
Actually, no.
“Correlation does not imply causation.”
Although it would be very easy to blame the vaccine, if you keep in mind that the saying is actually “correlation does not imply causation,” maybe you will do a little investigating and see if something else is to blame.
Some things to consider and ask yourself:
- Do I really have measles? Remember that it is not uncommon to develop a fever and a rash about 7 to 12 days after getting an MMR vaccine. This is a very common, mild vaccine reaction. It doesn’t mean that you have measles or even a mild case of the measles.
- Was I recently exposed to someone with measles? If you were vaccinated because you were exposed to measles during an outbreak, then there is a good chance that the vaccine hasn’t had a chance to work yet and you actually developed measles from being exposed to the wild virus.
- Do I have the wild type or a vaccine strain of measles? Testing can be done to tell which strain of measles you have and to see if it is a wild type or vaccine strain.
Are there any examples of folks having wild type disease if they get sick shortly after being vaccinated?
Not surprisingly, there are a lot of these types of examples.
“Vaccine strains are poorly or not transmissible and prompt differentiation between wild-type and vaccine strains allows for optimal management and public health action.”
Pabbaraju et al on Simultaneous Detection and Differentiation between Wild-Type and Vaccine Measles Viruses by a Multiplex Real-Time Reverse Transcription-PCR Assay
What about examples of folks getting sick with vaccine strain measles and other diseases? Not so many.

Most of the published examples are case reports without evidence of a vaccine strain.
What about the kid in Canada that got measles after her MMR vaccine?
“We describe a case of vaccine-associated measles in a two-year-old patient from British Columbia, Canada, in October 2013, who received her first dose of measles-containing vaccine 37 days prior to onset of prodromal symptoms.”
Murti et al on Case of vaccine-associated measles five weeks post-immunisation, British Columbia, Canada, October 2013.
She had symptoms of measles and a vaccine strain and was reported as “the first case of MMR vaccine-associated measles.” Well, at least the first case that occurred so long after getting vaccinated. Still, they note that “clinically significant vaccine-associated illness is rare.”
What about all of the people in California and Michigan who supposedly had vaccine-strain measles?

Anti-vaccine folks made that up!
When It’s a Wild-Type Virus
What’s the most obvious evidence against the idea that vaccines and shedding are responsible for causing outbreaks?
For one thing, despite the recent uptick, cases of vaccine-preventable diseases are way down from the pre-vaccine era. That’s not what you would expect if vaccine-induced disease was common or if contacts of those who were recently vaccinated could easily get sick from shedding.
And we have evidence against vaccine induced disease.
When kids get chicken pox shortly after being vaccinated, they often have a wild strain. They don’t have breakthrough chicken pox.
“All of 57 vaccinees with breakthrough varicella, clinically diagnosed on the basis of a generalized maculopapular or vesicular rash, in which there was amplifiable DNA [corrected], had wild-type VZV infection based on analysis of viral DNA. “
LaRussa on Viral strain identification in varicella vaccinees with disseminated rashes.
Same thing with measles.
Want to avoid these situations in which you could get a wild strain of a vaccine-preventable disease?
Don’t skip or delay your child’s vaccines!
More On Wild-Type and Vaccine Measles Viruses
- Do They Really Just Guess at Which Strain to Put in the Flu Vaccine?
- Are Mutant Strains of Polio Vaccine Now Causing More Paralysis Than Wild Polio?
- Was the Measles Outbreak in Michigan Caused by Vaccine-Strain Measles?
- Who Needs an MMR Vaccine?
- More Measles Myths
- Who Is ‘Patient Zero’ in the 2019 Measles Outbreaks?
- Diagnosing Vaccine Injuries
- Vaccine Injuries vs Coincidences
- Study – Differentiation of oka varicella vaccine strain from wild varicella-zoster virus strains isolated from vaccinees and household contact.
- Study – Differentiating the wild from the attenuated during a measles outbreak
- Study – Simultaneous Detection and Differentiation between Wild-Type and Vaccine Measles Viruses by a Multiplex Real-Time Reverse Transcription-PCR Assay
- Study – Case of vaccine-associated measles five weeks post-immunisation, British Columbia, Canada, October 2013
- Study – Viral strain identification in varicella vaccinees with disseminated rashes.
- Local public health response to vaccine-associated measles: case report
- Vaccine‐associated measles in an immunocompetent child
- Is the measles outbreak that occurred in Disney Land of a different strain than what’s in the vaccine?
- Genotypes, Serotypes and the MMR: Cognitive Dissonance in Action