The two vaccine candidates that were tested in monkeys consisted of a DNA vaccine and a purified, inactivated virus vaccine.
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“This gives us substantial optimism moving into human trials”, said Barouch, who directs the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston.
The two other experimental vaccines described in the new report also sparked an immune response in monkeys.
“Whilst these vaccine studies are promising there are some really important questions that need to be addressed”, said Jonathan Ball, professor of molecular virology at the University of Nottingham. His agency started injecting people with a test vaccine on Tuesday.
But British experts were clear that any of the vaccines would take time to develop. This news comes after the United States Department of Defense (DoD) confirmed more than 30 cases of Zika among U.S. troops. DNA vaccines like this one do not contain infectious materials and have displayed high levels of safety in clinical trials for other diseases. Florida health officials reported that they had discovered about a dozen cases of Zika transmitted locally by mosquitoes, and the CDC issued a rare warning for pregnant women to stay away from the Miami area where the cases were logged. But it can cause severe birth defects, including microcephaly, a condition in which babies are born with small heads and partially developed brains, and death to affected fetuses. Specifically, the Latin America epidemic could leave large portions of the population immune, substantially reducing transmission as early as next year-and making it more hard to determine whether a vaccine can prevent spread.
Wednesday, Health and Human Services Secretary Sylvia Burwell said clinical trials on a vaccine for the virus may be delayed because the National Institutes of Health will run out of these repurposed funds by the end of this month. Zika infections in adults may result rarely in Guillain-Barré syndrome.
However, the study showed that “all strains of Zika virus have identical surface antigens and therefore are the same serotype”.
That vaccine, developed at the Walter Reade Army Institute of Research in Silver Spring, Maryland, is expected to begin human testing in October. In one, a single and harmless Zika virus gene is stitched into a loop of DNA. The vaccine based on the whole, killed virus will go into human trials this autumn.
The adenovirus vector-based vaccine which is based on the same principles DNA vaccine, with only a fragment of Zika virus DNA being introduced into the body to trigger an immune response, proved particularly interesting to scientists.
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Further investigation confirmed that Zika infection is a cause of microcephaly, and as a result, the WHO declared this association a Public Health Emergency of International Concern in February of this year. He said, “The situation is getting critical”, saying a vaccine is “well within reach”, but could be delayed by lack of funding.
