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Carrington College Blog

Orphan vaccines may save wild ape populations

June 5, 2014

Orphan vaccines may go a long way toward treating wild chimpanzee populations.The Ebola hemorrhagic fever virus poses a significant threat to human and primates such as gorillas and chimpanzees. In fact, the latest Ebola outbreak in West Africa has infected more than 250 people and claimed the lives of more than 170.1 As a deadly threat to the health of world populations, it is high on the priority list for finding a treatment. A group of medical researchers have been successful with an Ebola vaccine developed specifically for captive chimpanzees. The hope, however, is to expand the application of the vaccine to human patients.

The dangers of Ebola

Ebola is one of the most deadly viruses on the planet. The World Health Organization estimates that Ebola outbreaks have a fatality rate of up to 90 percent.2 It is most prevalent in small African villages that are located in and around dense rainforests. The disease is highly contagious and spreads initially through the human handling of infected animals. Gorillas, chimpanzees, fruit bats, porcupines and forest antelope found ill or dead on the rainforest floor are prime candidates for spreading the disease. Ebola is then spread through human-to-human contact in any number of ways. Often medical workers treating infected patients will contract the disease, or mourners at a funeral ritual that come into contact with the body may become infected. Given that there is an incubation period of anywhere from two to 21 days, individuals often go for weeks without displaying any symptoms.2 During this time, the infected people often unwittingly spread the Ebola virus to those they come into contact with.

Using “orphan” vaccines

Currently, there is no registered Ebola vaccine for humans or animals, though a team of researchers is working to change that. Scientists at Cambridge University in the United Kingdom have found great success using an “orphan” vaccine to boost the immune systems of chimpanzees.3 So-called “orphan” vaccines are those that have not undergone the rigorous testing required for human use.

The vaccine was first created by a pharmaceutical company known as Integrated BioTherapeutics. The Cambridge research team got ahold of vaccine samples and injected them into captive chimps to see how their immune systems would respond. They found that treated chimps had a surplus of the antibodies necessary for attacking the Ebola virus. While the research team did not expose the chimps to Ebola directly, they found that the antibodies harvested from the chimps’ blood was successful in defeating the disease in laboratory mice.

While the proposed Ebola vaccine can’t be used on humans at this time, it may be a godsend for wild apes that are succumbing to human diseases more and more. An outbreak in 2007 alone decimated one third of the gorilla population in the entire world.  As researcher Peter Walsh put it, “Half of deaths among chimps and gorillas that live in proximity to humans are from our respiratory viruses. For us it’s a sore throat – for them it’s death.”3 Thus, many conservationists have described an “ethical debt” that we as humans owe to these animals, a debt that may be repaid should this new vaccine be successful.

The question of responsible conservation

The success researchers have had treating captive chimps with the new vaccine brings into focus a central conservationist dilemma. On the one hand, conservation efforts have historically taken what is called a “Garden of Eden” approach.4 This refers to the idea of allowing nature to run its course with minimal disruption from human activity. The biodiversity of the world is the result of billions of years of evolution, a process that necessitates the extinction of some species in order to make room for those that are better adapted. Therefore, conservation efforts are not necessarily concerned with saving every single species, a goal that would ultimately prove impossible, but rather, with allowing the natural processes to continue uninterrupted.

As such, many conservationists are hesitant to introduce anything into the wild as drastic as a new vaccine. Even though the Ebola virus poses a significant threat to wild gorilla and chimpanzee populations, introducing a human-created vaccine into the natural ecosystem flies in the face of the “look but don’t touch” approach of many conservationists. Those in favor of applying the vaccine to wild animal populations cite the damage that humans have already done to the natural ecosystem. In their view, humans have already disrupted the natural order, and now we owe it to the animal population to fix it if we can.

Those entering into a healthcare career should know about the current state of various vaccinations. Knowing of any international outbreaks of deadly diseases such as Ebola will keep you prepared for the demands of working in the healthcare industry. In addition, the work being done with orphan vaccines presents exciting new opportunities for those interested in animal medicine.

1 “Ebola virus spreads, kills at least 4 in Sierra Leone,” CBS News,

2 “Ebola virus disease,” Fact Sheet No. 103, April 2014,

3 “Ebola vaccine success highlights dilemma of testing on captive chimps to save wild apes,” University of Cambridge, May 26, 2014,

4 “The Garden of Eden Endangered: The Ecology and Biology of Conservation,” Carlos M. Duarte de Quesada, OpenMind,