Everything We Know About the Zika Virus, the First Worldwide Health Panic of 2016

We're not even a month through 2016, and already we have a worldwide health panic: The Zika virus, an ailment that is often symptomless but can lead to birth defects when it infects pregnant women, is "spreading explosively" according to the World Health Organization. When WHO says anything is doing anything explosively, that's bad.

The virus, which has in the past been mostly restricted to warmer parts of Africa and Asia and is transmitted by mosquito, is moving all over the world—one study in The Lancet predicted that it would find its way to areas where 60 percent of Americans live. The National Institutes for Health wrote on its blog:

"During the year, 9.9 million travelers left 146 Brazilian airports near areas known to be conducive to Zika virus transmission for destinations around the world. North and South American countries were the most-popular destinations (representing 65 percent of travelers) followed by those in Europe (27 percent) and Asia (5 percent). The most-popular travel spot was the United States, with more than 2.7 million people making the trip."

The rapid spread of Zika has WHO preparing to meet on Monday to decide if this constitutes a public health emergency. If the answer is "yes," it will be the first such emergency since the Ebola outbreak. Dr. Margaret Chan, the director of WHO, told the BBC that Zika had gone "from a mild threat to one of alarming proportions."

Zika was first discovered in 1947, but is new to the Western Hemisphere, and the fact that Zika can be linked to birth defects is causing people here to freak out. Specifically, it's been linked to microcephaly, which causes babies to be born with tiny heads and brain damage. In one northeastern state in Brazil, there are typically nine infants born with it per year, but by November, the New York Times reports, there were 646. Officials in Brazil, Jamaica, Colombia, and El Salvador have urged women to put off pregnancy until the crisis has abated—advice that's a little difficult to follow since access to birth control is hard to come by in these countries, and abortion is banned in some of them.

But if Zika has been around for decades in Africa and Asia, why are scientists just now noticing that it's linked to birth defects? "We've never seen this linkage with birth defects before, because now its in a different environment," Jared Aldstadt, a professor at the University at Buffalo who studies medical geography, told me. "Maybe its just a better health care system, so it can be recorded, but it's probably more that, in the places where Zika is endemic, the people getting infected are children, so it wouldn't really overlap with pregnancy."

It's unclear how the virus spread outside of its ordinary regions. The Centers for Disease Control (CDC) have advised pregnant women not to travel to most of South America and the Caribbean, as well as Mexico. For non-pregnant people, Zika is often asymptomatic, but can result in rashes, or joint paint, or fever.

Senator Kirsten Gillibrand has already wrote to the NIH urging it to come up a vaccine for the virus due to its "imminent threat" to the United States. Dr. Anthony S. Fauci, director of the National Institute of Allergy and Infectious Diseases said during a news conference that it was unlikely that one would be available for a few years.

One of the lead developers of the vaccine, however, told Reuters today that such a vaccine might be ready before the end of the year. Gary Kobinger said that it was designed to mimic Zika. "When the real thing comes in," he said, "then the antibodies are there, the immune system is primed, it's ready to attack right away."

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