Vaccination of small Asian mongoose (Herpestes javanicus) against rabies.

Oral vaccination of free-ranging wildlife is a promising technique in rabies control. The small Asian mongoose (Herpestes javanicus) is an important reservoir of rabies on several Caribbean islands, but no vaccines have been evaluated for this species. Captive mongooses were used to test the safety and efficacy of the commercially licensed vaccinia-rabies glycoprotein (V-RG) recombinant vaccine and a newly developed genetically engineered oral rabies virus vaccine (SPBNGA-S). In one study using V-RG, no vaccinated animals developed detectable rabies virus-neutralizing antibodies, and all but one died after experimental challenge with rabies virus. In contrast, all animals given SPBNGA-S demonstrated seroconversion within 7 to 14 days after vaccination and survived rabies virus challenge. On the basis of these preliminary results indicating the greater efficacy of SPBNGA-S vs. V-RG vaccine, additional investigations will be necessary to determine the optimal dose and duration of vaccination, as well as incorporation of the SPBNGA-S vaccine into edible bait.

Development of a GIS-based, real-time Internet mapping tool for rabies surveillance.

BACKGROUND: Oral rabies vaccination programs have been implemented to control the spread of wildlife rabies in the United States. However, current surveillance systems are inadequate for the efficient management and evaluation of these large scale vaccine baiting programs. With this in mind, a GIS-based rabies surveillance database and Internet mapping application was created. This surveillance system, RabID, provides a new resource for the rapid mapping and dissemination of data on animal rabies cases in relation to unaffected, enzootic, and baited areas where current interventions are underway. RESULTS: RabID is a centralized database for diagnostic and demographic information collected by local, state, and federal agencies involved in rabies surveillance. The geo-referenced database remits data to an Internet-accessible mapping application that displays rabies surveillance data in relation to environmental and geographic features. CONCLUSION: RabID provides a pioneering example of the power of geographically based Internet-accessible, infectious disease surveillance. This surveillance system was developed from existing technology and is readily adaptable to other infectious diseases and may be particularly useful for zoonoses. The development and application of public health informatics technology may enhance the effectiveness of public health interventions and allow better evaluation of public health interventions.

Efficacy of rabies biologics against new lyssaviruses from Eurasia.

New causative agents of rabies continue to emerge as shown by the recent description of four novel lyssaviruses from bats in Eurasia, Aravan (ARAV), Khujand (KHUV), Irkut (IRKV), and West Caucasian bat virus (WCBV). The effect of rabies vaccination prior to exposure to these new lyssaviruses was investigated in two animal models (i.e., Syrian hamsters and ferrets). The hamsters were vaccinated intramuscularly with a commercial human or veterinary vaccine or with an experimental vaccinia-rabies glycoprotein recombinant vaccine. At 5 weeks after vaccination, animals were challenged with ARAV, KHUV, IRKV, or WCBV, or with a traditional rabies virus of dog/coyote origin. Previously vaccinated and rabies-naive ferrets were also challenged with the four new isolates. In addition, the combined effect of rabies immunoglobulin and vaccine after exposure to the four isolates was investigated in hamsters using commercially available human products or an experimental monoclonal antibody. Results showed reduced protection with pre-exposure vaccination and with conventional rabies post-exposure prophylaxis against all four new bat viruses. In general, protection was inversely related to the genetic distance between the new isolates and traditional rabies viruses. For example, the WCBV is the most divergent of these lyssaviruses, and neither pre-exposure vaccination nor conventional post-exposure prophylaxis provided significant protection. The potential impact of these new lyssaviruses on human and domestic animal health and the impact on the putative bat reservoir populations will require further field and laboratory investigation.

Oral vaccination of dogs with recombinant rabies virus vaccines.

Oral rabies virus (RV) vaccines are used to immunize a diversity of mammalian carnivores, but no single biological is effective for all major species. Recently, advances in reverse genetics have allowed the design of recombinant RV for consideration as new vaccines. The objective of this experiment was to examine the safety, immunogenicity and efficacy of recombinant RV vaccines administered to captive dogs by the oral route, compared to a commercial vaccinia-rabies glycoprotein (V-RG) recombinant virus vaccine. Animals consisted of naive purpose-bred beagles of both sexes, and were 6 months of age or older. Dogs were randomly assigned to one of six groups, and received either diluent or vaccine (PBS; V-RG; RV SN10-333; RV SPBN-Cyto c; RV SPBNGA; RV SPBNGAGA), with at least six animals per group. On day 0, 1 ml of each vaccine (or PBS) was administered to the oral cavity of each dog, at an approximate concentration of 10(8) to 10(9) TCID50. After vaccination, dogs were observed daily and bled weekly, for 5 weeks, prior to RV challenge. No signs of illness related to vaccination were detected during the observation period. Excluding the controls, RV neutralizing antibodies were detected in the majority of animals within 1-2 weeks of primary vaccination. Thereafter, all dogs were inoculated in the masseter muscle with a street virus of canine origin. All control animals developed rabies, but no vaccinates succumbed, with the exception of a single dog in the V-RG group. Review of these preliminary data demonstrates the non-inferiority of recombinant RV products, as concerns both safety and efficacy, and supports the suggestion that these vaccines may hold promise for future development as oral immunogens for important carnivore species, such as dogs.