BY THE NUMBERS
Global health officials thought they had measles on the run. From 2000 to 2016, deaths caused by the highly contagious respiratory disease dropped by 84 percent worldwide, thanks to a vaccine that can be 97 percent effective. Yet poverty and misinformation undermined this progress. Inadequate medical-delivery systems in developing nations meant many children had no access to immunization. And in some wealthy countries, like the U.S., unfounded fears about safety led some parents to forgo vaccination, leaving their own children—as well as babies and people with compromised immune systems—vulnerable to the virus, which causes a rash, a fever and, in rare cases, even death.