In experiments by scientists at the army research unit, Tekmira reported last November, most animals infected with lethal amounts of Ebola survived when given the RNA product. The survival rate was 83 percent when the animals were treated 24 or 48 hours after infection and 67 percent when they were treated 72 hours after.
“It is amazing how well that works in non-human primates,” said Ebola researcher Thomas Geisbert of the University of Texas Medical Branch, who has conducted several studies of the company’s drug in monkeys.
Last month, Tekmira announced that its early-stage human trial had been put on hold by the U.S. Food and Drug Administration, which had concerns about the drug’s safety. Tekmira declined requests for an interview.
Profectus BioSciences has also tested its Ebola vaccine in monkeys, with good results, said Eldridge.
In a study with scientists at government biomedical research centers and the Pentagon, Profectus found that a single intramuscular injection protected all of the rhesus monkeys exposed to Ebola three weeks later. The company hopes to launch a human trial to assess the vaccine’s safety within the next 12 months, Eldridge said.
An experimental vaccine similar to Profectus’s, developed by academic and government scientists, was rushed into emergency use only once. In 2009 a scientist in Germany working with Ebola-infected guinea pigs pricked her finger with a syringe containing the virus. The vaccine was flown from Canada, one of the sites where it was being developed.
“She got that vaccine in less than 40 hours and survived,” said Geisbert, though it’s impossible to know whether that was because of the vaccine. “She lived. That’s all I care about.”
With greater financial support, scientists said, Ebola treatments could be ready for use sooner. For less than $10 million, said Vanderbilt’s Crowe, four or five of the experimental drugs could be ready for testing within in four months.
All of them seem to be effective only in a small window after exposure, however.
“Nothing on planet Earth is going to work if somebody comes in with full-blown Ebola hemorrhagic fever and they are 24 hours or 72 hours from death,” said Geisbert. “The damage has been done.”[eap_ad_3]