The National Institutes of Health has the green light to begin testing a new Ebola vaccine in humans, and data showing the vaccine’s safety and ability to provoke an immune response should be available by the end of the year.
Whether those data are enough to make health officials confident to give the vaccine to people in the field remains to be seen, National Institute of Allergy and Infectious Diseases director Anthony Fauci said on a conference call Thursday morning.
Once the data are available, Fauci said, “the most scientifically sound thing would be to proceed in a study that determines further safety and efficacy. But it’s impossible to predict when people can have it to use.”
Fauci called the efforts an “all-hands-on-deck response” to a public health emergency that has claimed at least 1,500 lives so far.
Fauci cautioned that the vaccine, if and when approved to use more widely, would likely first be given as a single shot to laboratory and healthcare workers treating people stricken with Ebola. It was developed by NIH and Okairos, a Swiss biotech company that GlaxoSmithKline acquired in 2013 for $325 million.
The trial, which begins next week at the NIH in Bethesda, MD, aims to enroll 20 healthy volunteers. Other trials are on tap, too, with a slightly different version of the vaccine.
The NIAID will start a second trial in October, and a public-private consortium is gearing up for a trial conducted in the United Kingdom, Mali and the Gambia. That effort is being funded by a $4.6 million grant from the Wellcome Trust, the Medical Research Council (MRC) and the UK Department for International Development.
It’s the first time this particular vaccine will be given to humans, but it’s not the first Ebola vaccine tested in humans—the NIH has run at least four other trials in recent years. They all delivered the same fragment of the Ebola virus meant to train the body’s immune system to fight infection, but they had different delivery mechanisms—known as vectors in vaccine-speak—that carried the Ebola fragment into cells. None of those previous trials advanced beyond Phase 1.
In the new efforts, the NIAID trial to begin next week carries fragments of two different Ebola strains: “Zaire,” which is causing the current outbreak, and “Sudan.” The second NIAID trial and the UK consortium trial will test a version with just the Zaire strain.
The Ebola fragments won’t, or shouldn’t, cause infection; vaccines work on the same principle used when investigators give a police dog an item of clothing to track the smell of a suspect. The virus fragment is meant to be just enough to help the immune system identify the real culprit when it invades.
Private companies have been working on clinical trial plans for Ebola treatments, but at least two of them have been interrupted recently. Sarepta Therapeutics of Cambridge, MA (NASDAQ: [[ticker:SRPT]]) scotched plans in 2012 for a Phase 1 trial after a stop-work order, and Vancouver, BC-based Tekmira Pharmaceuticals (NASDAQ: [[ticker:TKMR]]) had its Phase 1 trial placed on hold by the FDA before the agency reconsidered. Earlier this month, the company said the FDA might allow use of the drug in infected people because of the seriousness of the current outbreak.
Meanwhile, San Diego biotech company Mapp Biopharmaceutical has never formally tested its ZMapp treatment in people, but three Western aid workers who were infected in West Africa were administered doses and flown back to their home countries.
Two of them, both Americans, survived and are no longer in the hospital. The third, a Spaniard, did not survive.
