As of August 5, 2014, the World Health Organization is reporting more than 1,700 confirmed or suspected cases of Ebola in four different countries, including 932 deaths. It is the deadliest Ebola outbreak since the virus was first identified in 1976. The countries with the highest number of cases suffer from extreme poverty and a virtually non-existent health care system. The fatality rate is high because it generally strikes those already with poor health exacerbated by living conditions and lack of adequate health care. The arrival of two stricken American doctors in the United States represents the first time the virus has been within our borders.
All of this has raised the specter of the virus in the United States as well as interest as to why, after nearly 40 years, there hasnít been an antidote or a vaccine.
Itís not because scientists donít know about the virus. Since it was first discovered, the Ebola virus has changed very little. Scientists know that the virus is zootonic, meaning it is transferred from animals to humans. There are five subspecies of the virus, with four of them having caused disease in humans. Those four viruses originated in fruit bats native in Africa, which is where all Ebola outbreaks have occurred to date.
The virus can only be spread through direct contact with the bodily fluids of an infected person.† Because it can stay alive on surfaces for several days, it can be spread by touching surfaces where an infected person has been. The virulent side effects of the virus, including vomiting and diarrhea, can make containment difficult in the poor sanitary conditions of the affected areas. Health care workers lack the resources to keep themselves and others protected. The sheer volume of patients has stretched limited resources to the breaking point. Exhausted and overwhelmed, they do what they can to support patients, often to their own detriment.
In short, the virus is limited to a small population in mostly remote, poor areas in Africa. Until now outbreaks have affected only a few hundred people at most. This is why containment has worked because it has been easy to isolate the population.
These factors are also why there hasnít been a vaccine.
Scientists have been working on a vaccine for more than a decade. There are currently several preventive therapies at various stages of development. Thus far, they have been very successful in nonhuman primate test subjects.† The vaccines have been developed by small companies and there are possibly five that are ready for human test subjects.
All they need is money.
Big pharmaceutical companies have little interest in spending research and development dollars on something that will bring them little money. The affected people are poor and there would be little chance to extract a large profit for a drug that would be limited to one geographic area. Human test trials are expensive and any money would have to come from governments. Nations with research funds outside of Africa are also similarly disinclined to spend money on something that, quite frankly, just doesnít affect them.
Preventing the death of poor people in Africa is not a profitable business model.
There are some practical considerations, however. While it would make sense to inoculate health workers as a preventive measure, it would be difficult to access the populations that are most at risk of contracting the virus. The remote locations, limited health care infrastructure and fear of outside medicine are the greatest impediments to mass inoculation. Vaccines have a limited shelf life, so mass production would not be prudent and itís not possible to produce them on demand.
The United States Department of Defense and the National Institute of Health (NIH) have provided the most government funding for the research so far. The interest is not altruistic. The focus has been to understand the virus and development of antidote or vaccine in the event the Ebola virus was to be used for biological warfare.
Recently, two American doctors who contracted the virus while working in Liberia were treated with an experimental therapy. Both of them responded well to the treatment due to the medical care they are now receiving in Atlanta. While the controversial treatment has raised hopes for a possible solution, including financial investment into the company that developed it, there is still reason to remain cautious.† The two doctors were healthy when infected, now have access to excellent medical care and are white.
They are not the typical Ebola patients and their response cannot be expected to translate to the general affected population.
The high number of health care workers being infected with the Ebola virus, coupled with the high rate of international travel, has caused concern about the spread of the virus to the west.† Post infection therapies would still be difficult to administer for the same reasons that a vaccine would be. Furthermore, due to the rapid nature of how the virus replicates, it would have to be administered quickly after contracting Ė something not easily done in remote areas. Most believe that focus on an easy to administer, long acting vaccine would be the best approach.
Late†Wednesday, the FDA issued an emergency fast track approval for Phase I human trials for the most advanced Ebola vaccine. The approval will allow†clinical trials to begin as early as September. The experimental vaccine was developed by a research arm of the NIH called the Vaccine Research Center. Even with the fast tracking, the earliest a vaccine would be available would be late 2015 and that is only if all goes well during the trials. Still, this is much quicker than the average 10 years it takes to get most new vaccines to market.
People will not be infected with the virus during the trials. If the vaccine is proven to be safe and effective, healthcare workers would be the first to receive the vaccine. The NIH is working with other researchers that are close to human clinical trials and will be seeking approval for those to move forward as well.
Photo: Ebola virus via Thinkstock