Disseminating herpesvirus-based vaccines to target zoonoses in wild animal transmission and reservoir species

Many human infectious diseases originate as zoonoses from wildlife reservoir and transmission species. Human outbreaks of SARS and MERS, henipaviruses, and Ebola and Marburg viruses have all involved either direct or indirect... [ view full abstract ]

Many human infectious diseases originate as zoonoses from wildlife reservoir and transmission species. Human outbreaks of SARS and MERS, henipaviruses, and Ebola and Marburg viruses have all involved either direct or indirect transmission from wild animals. Changes in human behavior are rapidly increasing the rate of emerging infectious disease outbreaks, particularly in healthcare poor, wildlife host species rich regions of Africa, Asia and South America. Many of these emerging pathogens are potentially controllable by vaccination. However, the unpredictability and infrequency of human outbreaks, combined with their localization to under-resourced regions that commonly involve only a relatively minor proportion of the total human population has been a substantial hurdle to the development of vaccines for human use. Vaccination of wildlife species involved in zoonotic transmission is an alternative strategy that has proved successful for the control of infectious disease in wildlife transmission species, such as rabies in wild foxes and raccoons. However, these vaccination strategies rely on baiting or darting of animals with conventional vaccines that require inoculation of each individual animal, and are therefore are less suitable for use in non-temperate environments or inaccessible animal populations. Disseminating herpesvirus-based vectors are a new kind of vaccine that have the potential to overcome these problems due to their ability to spread immunity from animal to animal without the need for direct inoculation. This vaccination approach takes advantage of the evolutionary pressure imposed on herpesviruses to spread through their animal host, but then uses molecular engineering of the vector to enable simultaneous spread of immunity against infectious disease. Such disseminating vaccines may have the potential to solve many existing and currently intractable large-scale problems that beset areas of conservation, biodiversity, human health and the environment that are not amenable to control by conventional vaccines.