ROBERT SIEGEL, HOST:
Florida health officials say another baby has been born with severe birth defects caused by the Zika virus. It is the fifth case in the U.S. The mother caught the disease in Haiti. So far about 800 people in the U.S. have had the disease, all related to travel. There's no vaccine yet, but scientists say that they're making good progress. As NPR's Michaeleen Doucleff reports, a new technology is making vaccine development faster than ever.
MICHAELEEN DOUCLEFF, BYLINE: Biochemist Joseph Kim says he first heard about the Zika virus, and what it could be doing to babies last fall.
JOSEPH KIM: As soon as we saw the hint of microcephaly, that's when we decided to develop a vaccine for Zika.
DOUCLEFF: Kim is the president of Inovio, a biotech company in Pennsylvania that makes experimental vaccines. Within months, they had a shot that protected monkeys from Zika. And now they've got the first approval from the Food and Drug Administration to test it in people. A small study begins this summer.
KIM: This is a 40-subject study. All subjects will receive three injections into the skin.
DOUCLEFF: And from that they'll be able to tell if the vaccine is safe. If so, they'll start a larger trial in South America or the Caribbean by the end of the year. In many ways, Inovio has done what seemed impossible a few years ago. They've created a promising vaccine in just a few months, and they're not the only ones to do it. Today, researchers at Harvard Medical School report in the journal Nature two experimental vaccines that completely protect mice from Zika. Dan Barouch, who led the study, says he was shocked at how well the vaccines worked.
DAN BAROUCH: Certainly the current data are very encouraging and certainly increase the optimism that the development of a Zika vaccine for humans is likely going to be achievable. We were very, very pleased.
DOUCLEFF: One reason scientists have created these experimental vaccines so fast is they're using a new technology. It's called DNA vaccines.
ANTHONY FAUCI: It is really the vaccine trend of the future.
DOUCLEFF: That's Dr. Anthony Fauci at the National Institutes of Health. He says traditional vaccines, like for the flu or the measles, contain the whole virus. It's crippled or inactivated, but to make the shots you have to grow up huge batches of live virus. It takes time to get approval for this because working with live viruses can be dangerous. But a DNA vaccine contains just a tiny piece of a virus's genetic code, a harmless piece of DNA.
FAUCI: So it's a simpler, more efficient, and ultimately generally in the category of safety, a more safe type of an approach.
DOUCLEFF: Fauci says they've been working on this technology for years, but for these vaccines to work they had to get the DNA not just into the bloodstream, like a traditional shot does, but directly into cells. And for that they had to develop a whole new way of delivering vaccines.
FAUCI: There's a device that actually shoots the vaccine in through the skin without necessarily using a needle. It's kind of like a jet stream that puts the vaccine right through the skin into the tissue.
DOUCLEFF: Fauci says researchers at NIH are also working on a DNA vaccine for Zika. They hope to begin clinical trials in a few months. That means there are four vaccines showing promise. If all goes well, Fauci says, one of these should make it through approval in about a year and a half. Michaeleen Doucleff, NPR News.
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