Three Kinds of Vaccines Protect Monkeys from Zika

“What’s the timeline been on the development of these Zika vaccines?” I asked Nelson Michael, a colonel in the U.S. Army Medical Corps and the director of the HIV research program at the Walter Reed Army Institute of Research. He's been working on them since February, and now has published a new paper, with colleagues, reporting that their vaccines were successful in rhesus macaque monkeys.
“Now don’t laugh,” he said. “Let’s go back to 1893.”
That’s when Walter Reed was founded, albeit under a different name. Walter Reed—the person—studied yellow fever, “which is a flavivirus, much like Zika,” Michael says. Reed helped prove that yellow fever is spread by the Aedes aegypti mosquito, as is Zika.
“We always think of flaviviruses at our institute,” Michael said. So when the Zika outbreak ramped up early this year, Michael and his friend Stephen Thomas, a flavivirus expert at Walter Reed, started to work on developing a vaccine.
They created what’s called a whole-kill vaccine, or a purified inactivated virus vaccine. That’s when you take a living virus, kill it with formaldehyde, remove the formaldehyde, and then inject the dead virus into an animal to get an immune response.
Little did Michael and Thomas know that their friend Dan Barouch at Harvard Medical School was also working on a vaccine at the same time—a DNA vaccine, which uses the genetic material that produces the envelope around the virus to spur an immune response.
One day in March, Barouch called Michael to ask if they perhaps were working on a Zika vaccine, because he wanted to test more than one kind.
“I said, ‘Are you kidding me?’” Michael says.
So they worked together, and in June, they published results in Nature that their vaccines had worked in mice. And in the new study, published in Science on Thursday, both the whole-kill and the DNA vaccines “provided complete protection” to vaccinated monkeys, the study reads, as did a third kind of vaccine in which you “take a harmless virus and you basically make it a bus by sticking in genes from a pathogen,” Michael says. The unvaccinated monkeys showed traces of the virus in their blood, urine, cerebrospinal fluid, cervical fluid, and rectal fluid up to a week after exposure.

source :http://www.theatlantic.com/

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