ZMapp's maker, Mapp Biopharmaceutical Inc., of San Diego, has said the small supply of the drug is now exhausted and that it will take several months to make more. The drug is grown in tobacco plants and was developed with U.S. government support.
Kobinger said it takes about a month to make 20 to 40 doses at a Kentucky plant where the drug is being produced. Officials have said they are looking at other facilities and other ways to ramp up production, and Kobinger said there were plans for a clinical trial to test ZMapp in people early next year.
The monkey study involved scientists from the Canada health agency, Mapp Biopharmaceutical, the U.S. National Institutes of Health and the United States Army Medical Research Institute of Infectious Disease.
Eighteen monkeys were given lethal amounts of Ebola in a shot, then received three intravenous doses of ZMapp, given three days apart starting three to five days after they were infected. Some were showing severe symptoms such as excessive bleeding, rashes and effects on their liver.
All treated with ZMapp survived; three other infected monkeys who did not get the drug died within eight days.
Primates have been good stand-ins for people for many viral diseases, but how well they predict human responses to Ebola, "we just don't know," said Dr. Cameron Wolfe, a Duke University infectious disease specialist. The study also "tells us nothing about side effects" people might have, he added.
Still, it was encouraging that even monkeys with severe symptoms got better, said Wolfe and Erica Ollmann Saphire, a Scripps Research Institute professor who has worked with some of the study leaders on antibodies to Ebola.
"The treatment window in humans needs to be established in a well-controlled trial" that also would explore the correct dose of ZMapp in people, Saphire wrote in an email. "Given its tremendous efficacy in the nonhuman primates, I don't see how it couldn't be helpful in people."
Ebola info: http://www.who.int/mediacentre/factsheets/fs103/en/
Vaccine study info: http://www.niaid.nih.gov/news/QA/Pages/EbolaVaxQA.aspx
Marilynn Marchione can be followed at http://twitter.com/MMarchioneAP