In February 1996, a violent disease swept northeastern Gabon with a fury. Eighteen people in a small village called Mayibout II, near the border of the Democratic Republic of Congo, suddenly became ill after they found and scavenged a sick chimpanzee, later determined to be infected with the Ebola virus. Their symptoms included fever, headache, vomiting, bleeding in the eyes, bleeding from the gums, hiccupping, and diarrhea. All eighteen were evacuated to a regional hospital downriver. Four died soon after. The bodies were then returned to Mayibout II and buried without special safeguards. Secondary cases of infection occurred among individuals who were in close proximity to their sick friends and family or in managing the dead bodies. In all, thirty-one people became ill, twenty-one people died – a mortality rate of 68 percent. [1]
In February 1996, a violent disease swept northeastern Gabon with a fury. Eighteen people in a small village called Mayibout II, near the border of the Democratic Republic of Congo, suddenly became ill after they found and scavenged a sick chimpanzee, later determined to be infected with the Ebola virus. Their symptoms included fever, headache, vomiting, bleeding in the eyes, bleeding from the gums, hiccupping, and diarrhea. All eighteen were evacuated to a regional hospital downriver. Four died soon after. The bodies were then returned to Mayibout II and buried without special safeguards. Secondary cases of infection occurred among individuals who were in close proximity to their sick friends and family or in managing the dead bodies. In all, thirty-one people became ill, twenty-one people died a mortality rate of 68 percent. [1]
Seven years later, I sat in a laboratory assessing under a microscope the health of E. coli cells that had been transformed with one particular gene from the Ebola virus. It was one of many experiements I conducted to determine the best way to culture E. coli cells that have a toxic, immunologically suppressive glycoprotein in its cells. The Ebola gene came to be in my hands because I worked for a local CMO, at the time, and my company had a working collaboration with Dr. Gary Nabel of the National Institutes of Health's Vaccine Research Center and his team from the NIH.
Terrifying and Disruptive
Ebola is a perplexing disease oftentimes, contradictory to reason. Whenever outbreaks occur, the circumstances in the "hot zone" are constantly changing. Accidents happen. Aberrations appear. And with them new opportunities emerge, both for the virus and for those combating it.
While this experimental treatment has been in the works for years, research had been overlooked by much of the world because the Ebola virus itself had gone into hiding for nearly twenty years. The version of Ebola that is emerging now has a more powerful virulence than other strains, one of the reasons why the WHO has classified it as an, international health crisis. Dr. Tom Frieden, director of the CDC, said last week (Sept. 2) that, the challenge is that the number of cases is so large, the outbreak is overwhelming, what it requires is an overwhelming response, Frieden said. The virus is moving faster than anyone has anticipated, so that's why we need to move fast.
At least twenty-five organizations in San Diego are working on some aspect of the vaccine. The one closest to public release, developed by the pharmaceutical company Mapp Pharmaceuticals, but there are a number of organizations working in collaboration with National Institute of Health (NIH) and SAFC. Overall, scientists are optimistic a vaccine can be developed that will stop the outbreaks of Ebola, once and for all.
Genetics Holds the Key
Ideally, an Ebola vaccine would provide lifelong protection. But if the virus goes back into hiding like before, any lull in transmission could cause a lot of people to lose any immunity they have built up, leaving a much more disastrous situation if it returned. Ebola additionally has five sub-strains (each river valley appears to have its own version) and a vaccine has to block them all. And of course, the vaccine can leave no opening for the virus to develop resistance. Creating an Ebola vaccine is quite an undertaking.
One thing was known at the time this early vaccination work was done: the precise makeup of the Ebola genes. Anthony Sanchez of the Centers for Disease Control and Prevention decoded and published the precise genomes for six of Ebola's seven genes; a group of Russian scientists decoded the seventh.
Then, in July 2000, Dr. Gary Nabel of the National Institutes of Health's Vaccine Research Center and his team from the NIH and the Center's for Disease Control and Prevention said they had discovered that a particular glycoprotein being emitted by the virus, which seemed to be attacking the cells that line the blood vessels, called endothelial cells, causing them to leak [2]. This gave Nabel and his team at NIH a possible reason for much of the devastating hemorrhaging witnessed at peak infection. But it also provided, in Nabel's words, molecular target for potential new antiviral drugs and vaccines. [3]
Vaccines are sometimes created from viruses that have been weakened or killed so that they no longer cause disease. With a virus such as Ebola, any traditional vaccine would unlikely be accepted by market. So, Nabel and his team had to come up with a different plan. The Ebola vaccine that I helped to manufacture, was created using the gene that codes for this glycoprotein. However, earlier experiments showed that injections of this protein alone did not generate enough of an immune respone to protect the monkeys being tested. So in order to "rev up" their immune systems, Nabel and his team genetically engineered a weakened cold virus so that it contained this protein from the Ebola-Zaire strain. When both shots were used in tandem with one another, it did the trick, and the monkeys recovered [4].
While I can say that I have personally pondered the secrets of Ebola in the laboratory, really it's the healthcare workers in Zambia, Sierra Leone, Liberia, and Guinea right now who are coping with Ebola's victims. In fact, medical systems in Liberia, Guinea, and Sierra Leone are reportedly overwhelmed with people presently dying from Ebola. The World Health Organization (WHO) is reporting that 20,000 more people could become infected. Posters have been hung throughout the country, informing people of Ebola's causes and symptoms and the importance of medical intervention. All of West Africa, it seems has been mobilized to contain Ebola. It seems for now, their best course of action is to educate the public, then slow the spread of disease through quarantine.
This isn't going to be last outbreak. What can we be doing to stay ahead of the next one?
For the long term, we could all work a little harder to bend the arc of justice toward a continent where medical care is inaccessible for far too many, where fresh water is relatively scarce, where modern conveniences like electricity and roadways can be problematic. Infrastructure problems like these do more to make epidemics worse by undermining efforts to deliver quality care. What we are all witnessing at present, is not just Ebola. It's also the lack of adequate resources, hospitals, doctors, nurses, and medical supplies.
No one knows when this outbreak will be over or when the next one will happen. We only know a little bit about how the virus works, and we still have no way to effectively manage the disease. And we still do not know where in the wild the virus lurks.
Perhaps it is no wonder many are frightened of Ebola, even though it caused relatively few deaths over the past twenty-five years. We know very little about it - and people often fear what they do not understand.
SOURCES
[1] David Quammen, "Infectious Animals," NationalGeographic.com, October 2007, http://ngm.nationalgeographic.com/ngm/2007-10/infectious-animals/quammen-text-p5.html (September 2, 2014).
[2] Reuters, Study: Protein key to Ebola effects, MSNBC, July 31, 2000, http://www.msnbc.com/news/440043.asp(September 1, 2014).
[3] Study: Protein key to Ebola effects.
[4] Lauren Neergaard, "Monkey Study: Ebola Vaccine Works, Needs Booster," ABCNEWS.com, September 7, 2014, <http://abcnews.go.com/Technology/wireStory/monkey-study-ebola-vaccine-works-booster-25329227> (September 7, 2014).