At least 35 people, mostly children, have been diagnosed with measles in Washington state since January 1, prompting the state’s governor, Jay Inslee, to declare a state of emergency. Around 40 more have been diagnosed in New York this month, part of an outbreak there that’s seen at least 186 cases since October. Public health officials expect the outbreaks to spread further, and attribute both of them to the same problem: An increasing number of parents are refusing vaccinations for their kids.
Across the United States, children are required to be immunized from life-threatening diseases before they’re allowed to enter school or daycare. This not only protects the child from disease, but ensures that schools are safe places for immune-compromised kids and adults, as well as kids and adults who are medically unable to get vaccines. Vulnerable groups such as these rely on herd immunity, which is achieved when around 90 to 95 percent of the population is vaccinated.