There’s been a lot of speculation about whether low vaccination rates are feeding the 2015 U.S. measles outbreak, which as I write this stands at 145 cases across seven states. Well, we can stop speculating, because the numbers are in, and measles is taking advantage of pockets of inadequately vaccinated people.
Maimuna (Maia) Majumder is an engineering systems PhD student at MIT and computational epidemiology research fellow at HealthMap.
The 2015 Disneyland measles outbreak in the United States, which started in late December and spread to more than 100 people in just 6 weeks, has recently become the subject of substantial media scrutiny.
Measles is extremely infectious, exhibiting a basic reproductive number between 12 and 18—one of the highest recorded in history. This means that for every 1 case who gets sick in a totally susceptible population, 12 to 18 other folks get sick, too. Thankfully, when uptake of the measles vaccine is high enough in a given community, it’s almost impossible for the disease to spread—thus halting a potential outbreak in its tracks.
But what happens when vaccine rates aren’t high enough? …