Why are there many vaccinated kids in measles outbreaks?

As usual, the answer is in the proper analysis of data.

René F. Najera, MPH, DrPH


Epidemic curve of a fictional epidemic of measles at an elementary school.
In a fictional outbreak of measles, there are almost equal numbers of vaccinated and unvaccinated, proving the vaccine is effective.

A Fraud and Its Victims

In 1998, a team of researchers in Great Britain published a study examining the relationship between the MMR (measles, mumps, rubella) vaccine and autism. Or, as the study paper put it, “We identified associated gastrointestinal disease and developmental regression in a group of previously normal children, which was generally associated in time with possible environmental triggers.” One of those triggers was the MMR vaccine.

If you clicked on the link to the paper, you might have noticed the paper is retracted. It was retracted because it was found to be fraudulent, filled with inaccuracies and with questionable ethics practices. Nevertheless, the damage was done. Anti-vaccine organizations and activists showcased the study and its authors as evidence that vaccines cause autism.

Vaccines do not cause autism, based on over years of subsequent (and expensive) studies trying to replicate the original paper’s findings and dispel myths about other vaccines.

In 2017, one of the principal investigators of the fraudulent 1998 study traveled to Minnesota. He met with parents in the Somali refugee community there. He allegedly explained to them his concerns about the MMR vaccine, and they believed him. Soon thereafter, MMR vaccine coverage for young children dropped. Not too long after that, a measles epidemic hit the community hard.

It would be the biggest measles epidemic in Minesotta in 30 years.

A Reasonable Fear

Why were parents concerned? First, their children were being diagnosed with a condition that was new to them: Autism. In many developing nations around the world — and in cultures where science and biology are not easily attainable as they are in the American educational system — the idea of autism is hard to understand.

Autism occurs on a spectrum, with some autistic people showing more developmental delay/disability than others. If you did not know that autism was a thing, you might think of a severely disabled autistic person as “brain damaged.” And you might think of a functional…



René F. Najera, MPH, DrPH

DrPH in Epidemiology. Associate/JHBSPH. Adjunct/GMU. Epidemiologist. Father. Husband. (He/Him/His/El)