Public health officials have just one tactic to battle the unrelenting Ebola virus outbreak in West Africa — quarantine — but as the disease continues to spread, scientists in Maryland are among those close to discovering other weapons.
Baltimore companies Profectus BioSciences and Paragon Bioservices, as well as researchers at the U.S. Army Medical Research Institute for Infectious Diseases at Fort Detrick in Frederick and the National Institutes of Health in Bethesda, have been part of efforts that have shown a handful of Ebola vaccine candidates are effective in monkeys.
But researchers here and around the world have struggled to advance the projects further because the relatively few number of cases offers little financial incentive for pharmaceutical companies. The current outbreak — the worst in history, having killed about 60 percent of the 1,300 infected since March — could help change that, researchers said. It already prompted the NIH to announce the launch of clinical trials of a vaccine candidate on humans in September.
Meanwhile, poor communication and understanding of the virus is allowing it to spread faster than efforts to contain it, according to the World Health Organization. That could mean the outbreak is far from over, said Dr. Randal Schoepp, a scientist at the Army's Frederick institute, in an interview from Liberia.
"I believe we're only seeing a small portion of the actual cases out there," Schoepp said of the outbreak. "It's putting a tremendous stress on the medical system, and there aren't even enough medical staff to take samples."
Two Ebola patients are about to enter the United States — a pair of U.S. aid workers suffering from the disease were to be flown to Atlanta for treatment in a high-security ward at Emory University Hospital, set up in collaboration with the Centers for Disease Control.
Schoepp is in the midst of a monthlong deployment to Liberia's Institute of Biomedical Research, where the Frederick resident and colleagues are running the only lab in that country capable of testing blood samples for Ebola. Other testing occurs in Sierra Leone and Guinea.
"Everyone is scared here," said Schoepp, chief of the Fort Detrick institute's applied diagnostics department. "We have had problems with drivers not wanting to go to hospitals and pick things up."
His daily infection control precautions include three pairs of gloves, hoods and face shields tucked in to a Tyvek bodysuit. At stores, customers are asked to wash their hands in chlorine before shopping, he said.
Fears of the disease don't stem from a lack of knowledge about its molecular biology or epidemiology, researchers said. Since its discovery in 1976 near the Ebola River in what is now the Democratic Republic of Congo, scientists have learned much about Ebola, which spreads through contact with blood or secretions of an infected person. The virus first attacks the lymphatic system, responsible for key immune system agents like T-cells, and is able to spread throughout the body before it is able to recognize the virus or mount an immune response.
Symptoms include sudden high fever, headache and fatigue, and, eventually, massive internal and external bleeding. Some of the five known strains of the virus can kill as many as 90 percent of those infected, typically by shock, renal failure or blood loss.
It is not known how outbreaks begin, but it is thought that the virus is carried by fruit bats and transmitted from animals to humans.
Scientists also have learned how to counteract the virus, if only in primates. At least four vaccines that have been tested in the U.S. use benign pieces of Ebola to trick the body into mounting a response to the virus, thus building immunity. The proteins that surround the Ebola virus' genetic information are instead bound to other viruses, which are either naturally harmless to humans or are weakened, or to other proteins so the body recognizes them as Ebola.
"They're each finding different mechanisms to get there, and they're all going to get there; however, I don't know how soon it will be," said John Dye, chief of viral immunology at the Fort Detrick research institute.
The potential vaccine Profectus is developing with the University of Texas Medical Branch at Galveston, for example, uses a live virus that also has been explored as a vehicle for other vaccines, including one Profectus is researching for HIV. While it can elicit a stronger immune response — and thus stronger immunity — than vaccines using weakened viruses, it also could pose safety concerns.
But if it's shown to be safe, its strength could make it a significant candidate for widespread adoption, said Thomas Geisbert, a professor of microbiology and immunology in Galveston. Profectus, which has labs in Dundalk, has a commitment from NIH to eventually test the vaccine's safety in clinical trials with human subjects.
"You don't have months and months and months for a vaccine to work." Geisbert said. "You need a fast-acting vaccine."
An NIH official said Thursday that a vaccine candidate it is developing in Bethesda would enter clinical trials on humans in mid-September. That vaccine uses an adenovirus, a type that includes the common cold, to deliver the Ebola proteins. But it's possible that vaccine could be less effective because many people have immunity to adenoviruses.
The Army's Frederick lab is working on two vaccines, one using a virus similar to the NIH's adenovirus, and another creating a "viruslike particle" that contains the Ebola proteins and others. Paragon, a contract lab in the University of Maryland BioPark, has worked with the institute on its vaccines for Ebola and Marburg, a similar virus.
While each of the four candidates has proved effective at building Ebola immunity in monkeys, research has stalled there.