Zika vaccines work in monkeys

Three experimental Zika vaccines protected monkeys against infection from the virus, an encouraging sign as research moves into studies in people.

The success in monkeys, which involved a traditional vaccine and two more cutting-edge ones, "brings us one step closer to a safe and effective Zika vaccine," said Dr. Dan Barouch of Beth Israel Deaconess Medical Center in Boston. "But of course, there's a lot more work to do."

Barouch and others reported the results in a paper released Thursday by the journal Science. One of the vaccines is expected to enter preliminary human studies this year.

At least two other vaccines have reached that point already. Inovio Pharmaceuticals announced last week that it had injected its first participant. The National Institute of Allergy and Infectious Diseases gave its first vaccine Tuesday. Both studies focus on assessing vaccine safety.

Efforts to develop a vaccine began after a massive Zika outbreak last year in Brazil, which showed that infection of pregnant women can harm fetal brain development.

In the monkey study, one vaccine followed the traditional approach, using a dead Zika virus to train the body for fighting off infection. It was injected into eight rhesus monkeys and followed by a booster shot a month later. A month after the booster, the monkeys got a dose of Zika virus.

None showed any sign of the virus in their blood for the week they were followed. In contrast, eight other monkeys that had gotten a sham vaccine became infected.

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