Two-part vaccine protects monkeys from Ebola

Macaques survive infection with deadly virus 10 months after receiving second shot

An experimental vaccine protects monkeys from infection with Ebola, even when the animals are exposed to the virus 10 months after getting the shots, researchers report September 7 in Nature Medicine.

The vaccine is undergoing safety testing in healthy human volunteers (SN Online: 8/24/14). The World Health Organization announced Friday that, once tested, this and another experimental vaccine could be given to health workers as soon as November to fight the Ebola epidemic raging in West Africa.

A team led by researchers at the National Institute of Allergy and Infectious Diseases in Bethesda, Md., and Okairos, a biotechnology company now part of GlaxoSmithKline, developed the candidate vaccine by placing genetic material from the Ebola virus into a chimpanzee common cold virus. A single shot protected four macaques when they were exposed to Ebola five weeks later.

Another set of four monkeys got the test vaccine shot plus a booster shot eight weeks later. The booster included Ebola gene segments incorporated into a poxvirus. All four animals evaded infection when exposed to Ebola 10 months after the booster shot.

The vaccine doesn’t use human cold viruses because many people have immunity to them and people’s immune systems may wipe out the vaccine before the body could engender a reaction to Ebola, the authors note.

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