How holes in herd immunity led to a 25-year high in U.S. measles cases
Too many unvaccinated people are helping the virus spread
Measles is so contagious that the virus can unerringly find the unvaccinated. That knack, combined with the number of people in the United States who haven’t been vaccinated against the disease, has given measles an opening that it hasn’t had in the country for decades.
U.S. measles cases have surged to a 25-year high of 704, the U.S. Centers for Disease Control and Prevention reported April 29. The record-breaking number of cases largely stems from an outbreak in Washington, which officials now say is over, and ongoing outbreaks in New York City and New York state. The vast majority of the cases, 88 percent, originated in close-knit communities that have low rates of vaccination, according to the CDC. And 503 of the 704 cases were in those who have not been vaccinated.