The Zika Virus Isn’t Just an Epidemic. It’s Here to Stay.

With an estimated 3 to 4 million people having come down with Zika virus ailments since infected mosquitoes reached the Americas some nine months ago, 23 countries and territories have reported cases, and there are some 4,000 babies that have been born with the skull-misshaping microcephaly, according to the World Health Organization.

“Last year, the virus was detected in the Americas, where it is now spreading explosively,” WHO Director-General Margaret Chan said in a speech Thursday to the organization’s Executive Board. “The level of alarm is extremely high.”