Could a vaccine aid in conserving great apes?
Apes are subject to “naturally” occurring pathogens like Ebola and Simian Immunodeficiency Virus (SIV) as well as some diseases we humans transmit. Both types of disease are important sources of mortality in wild chimpanzees and gorillas.
In a paper published in PlosOne (December 2011), Dr. Sadie J. Ryan and Dr. Peter D. Walsh present their findings based on an analysis of the consequences of non-intervention for infectious disease in African great apes. In short: wild great ape recovery from disease is slow, and a single outbreak can devastate a population.
We found that the predicted recovery time for this specific gorilla population from a single outbreak ranged from 5 years for a low mortality (4%) respiratory outbreak, to 131 years for an Ebola outbreak that killed 96% of the population. This shows that mortality rates comparable to those recently reported for disease outbreaks in wild populations are not sustainable.
Given the grave impact a single infectious disease outbreak may have on ape populations, the researchers evaluate how to best impede such outbreaks from occurring. Both non-interventionist actions, like limiting tourist access to apes and community health programs, as well as more direct actions like vaccination were proposed as ways to protect great apes from disease:
Based on our research here, we suggest that the great ape conservation community should pursue and promote treatment and vaccination, as weapons in the arsenal for fighting the decline of African apes. This should include rigorous assessments of both safety and cost-effectiveness, and should emphasize program sustainability, with particular attention to the training of African veterinary personnel.