This post comes via Know More, Wonkblog's social media site.
The graphic below, by Bonnie Berkowitz and Lazaro Gamio of The Washington Post, illustrates how measles spreads in an area without a vaccination program. The differently shaded squares represent four generations of infection, from Patient Zero (the darkest red square at the top left) to the people he or she infects, the people they infect in turn, and so on. The dark squares represent people who die from the disease.
Without vaccinations, each measles case will infect 12 to 18 other people on average every 10 to 14 days. You can see how quickly the disease spreads from the first generation (Patient Zero) to 12 to 18 people in the second generation, 144-324 people in the third generation, and 1728-5832 people in the fourth generation. That adds up to more than 6,000 infections, all within 40 days. In a country with substandard healthcare and malnutrition, up to 28 percent of those infected will die.
Now contrast that with a country with full vaccination: In that scenario the disease would spread to 0.8 people every 10 to 14 days, and less than .3 percent will die.
In a country like the U.S., where most people have been vaccinated but pockets have not, the disease would spread to 1.1 to 2 people every 10-14 days and less than .3 percent would die.
It's a great reminder not to take vaccinations for granted.