A Zika vaccine has moved a step closer after three promising candidates were successfully tested in monkeys.
The news comes in the same week officials in Florida said 14 people had been infected with the virus in Miami.
It was the first time transmission of the mosquito-borne disease, linked to serious birth defects, had been confirmed in the continental US.
Three different kinds of vaccine were tested for their ability to induce immunity to Zika in rhesus monkeys.
All three proved "strikingly effective" and produced no adverse side effects, said researchers.
Professor Dan Barouch, from Harvard Medical School, US, who led the study, said: "Three vaccines provided complete protection against Zika virus in non-human primates, which is the best animal model prior to starting clinical trials.
"The consistent and robust protection against Zika virus in both rodents and primates fuels our optimism about the development of a safe and effective Zika vaccine for humans."
One of the vaccines is based on a purified inactivated virus.
The other two are based on viral DNA, and a fragment of the infectious agent carried by another virus that has been rendered harmless.
The research is published in the journal Science.
British virus expert Professor Ian Jones, from the University of Reading, said: "The demonstration of protection against Zika infection in rhesus monkeys is not unexpected but is nonetheless welcome as a further step on the road to a human vaccine.
"Of the three vaccines tested here, the simplest, inactivated virus is the most likely contender for a full human trial.
"Only when that is done will we know if one shot is sufficient, if previous or co-circulating infections have any adverse effect on the outcome, and how long protection might last."
