A needle-free Ebola vaccine protects monkeys 100 percent of the time from the virus, even a year after they’ve been vaccinated, researchers reported Monday.
The vaccine uses a common cold virus genetically engineered to carry a tiny piece of Ebola DNA. Sprayed up the nose, it saved all nine monkeys tested for infection.
But now the research is dead in the water without funding, Maria Croyle of the University of Texas at Austin’s College of Pharmacy said.
“Now we are at the crossroads, trying to figure out where to get the funding and resources to continue,” Croyle told NBC News.
It’s only a small study, but the results are encouraging, said Croyle, whose findings are published in the journal Molecular Pharmaceutics and being discussed at the American Association of Pharmaceutical Scientists meeting in San Diego this week.
The logical next stage would be tests in people. Croyle says she’s seeking either a drug company, or the federal government, or both, to work with her team. The U.S. National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, has a vaccine development center that’s worked on other Ebola vaccines.
Several Ebola vaccines have been in the works for years. But until this current epidemic in West Africa, which has infected more than 13,000 people, there wasn’t a real push to bring such a vaccine to market and the main source of funding was U.S. biodefense programs aimed at protecting against a biological attack.
Croyle’s team had been working on this one for seven years.
“We are kind of under the radar,” Croyle said. The NIH and others were waiting for the results of the monkey trials.
The results were better than expected. The nasal vaccine targets cells in the nasal passages and in the lungs, and caused a body-wide immune system response. It affects what are called the mucosa, and means protection again the virus entering the eyes, nose and mouth, as well as through a cut in the skin.
Other Ebola vaccines have languished in the lab for years too, but research accelerated when it became clear the West African epidemic was far worse than previous outbreaks. Now at least six different vaccine trials are underway — three in the United States, one in Britain, one in Mali and one in Switzerland.
It’s not yet clear who would be vaccinated if the vaccines prove to be safe and effective in trials, but many experts believe it would make sense to start with health care workers, who are badly needed to care for Ebola patients and who are at high risk of infection themselves.
In Mali, the vaccine being tested is also made using a common cold virus called an adenovirus that does not make people sick. The trial has been set up quickly. Usually, it takes six to 11 months to get a vaccine trial started because of all the regulatory and ethical hoops. This one got started in two months.
Another one being tested uses an animal virus called vesicular stomach virus, or VSV, genetically engineered with a piece of Ebola virus. It was developed by Canadian and U.S. scientists and has been licensed to NewLink Genetics Corp.
Drug companies have opted not to develop Ebola vaccines on their own because the potential market was too small — before now, Ebola had only infected a few thousand people.
Croyle said her team’s vaccine may be easier to administer than the others because it’s needle-free — something that’s important because accidental needle injuries are one way health care workers are getting infected with Ebola. She also believes it may be stable at room temperature — an important factor in delivering a vaccine in hot areas without electricity.
"Nasal administration creates a stronger line of defense," Croyle said.
Another nasal spray vaccine has been gaining traction. It’s a flu vaccine made by MedImmune, and vaccine advisers now say it works better than injected influenza vaccines in children.
The U.S. Food and Drug Administration has a special process for approving vaccines against deadly infections such as Ebola. If a vaccine is shown to be safe in monkeys, it can be given to healthy human volunteers to test its safety. No one's exposed to the virus itself — instead, doctors look at their immune response to the vaccine to see if it looks like it would protect the body from infection.