Everything you need to know about measles
Measles went from a disease almost every child caught to one the vaccine nearly ended — and now it is coming back. Eight short lessons, quizzes, and a timeline that explain how, using numbers you can check from the CDC, WHO, and published research.
Eight lessons, start to finish
Read them in order or jump to what interests you. Your progress is saved on this device.
Module quizzes
Each quiz gives instant feedback and an explanation for every answer. Your best score is saved.
A timeline of measles
Key dates, from the first descriptions of measles to the outbreaks happening now. The larger dots mark turning points.
My progress
Tracked privately in your browser — nothing is uploaded anywhere.
Why this guide exists
Measles is one of the clearest examples of what vaccines do — and what happens when we stop using them. This free guide pulls the whole story into one place: what the virus is, what it does, and how the vaccine changed everything.
It is written for a general audience, not just for doctors. Every fact links to a primary source — the CDC, the WHO, or published research — so you can check it yourself. Read the lessons at your own pace, test what you learned with the quizzes, and use the timeline to see how measles has affected people for more than 2,500 years.
Author
Created by Rene F. Najera, DrPH, an infectious-disease epidemiologist and public health educator, to explain the evidence on measles in plain language anyone can follow.
Sources
Primary sources are cited within each module and timeline entry. Key references include the CDC History of Measles, the WHO Measles Fact Sheet, Düx et al. (Science, 2020) on measles origins, and Mina et al. (Science, 2019) on immune amnesia.
Verify everything — download the full source list
Every fact across the eight lessons and the timeline is collected into one references handout — with clickable links, organized by lesson. It also notes the two points where reliable sources disagree, so you can weigh the evidence yourself.
Download Sources & References (PDF)