As we've discussed in class, the fear of smallpox as bioterror weapon has stimulated research toward new treatments and vaccines. However, because the new treatments developed cannot be tested on humans, it is important to find comparable animal models to use in safety and efficacy trials.
In this study, scientists used rabbitpox to simulate smallpox due to its airborne transmission. Researchers found that when rabbits were exposed to low levels of the virus, the effects of rabbitpox on rabbits were similar to the effects of smallpox on humans. Transmission, incubation, prodromal phase, clinical signs, skin lesions, and complications were all comparable. Rabbitpox caused "viral dissemination, secondary lesions, and animal-to-animal transmission and lethality". Because these results are similar to what we know about human exposure to smallpox, the rabbits were seen to be a successful animal model for smallpox.
As with all animal models, using rabbits has its limitations. The paper notes that because there are no knock-out rabbit strains, it is difficult to study all types of disease pathogenesis and how the host-immune system might respond in various cases. In addition, their are few immunological reagents that can be used with rabbits. However, overall they found the rabbit to be an "excellent animal model" that will enable the testing of new vaccine and antiviral developments against smallpox.