Immunogenicity and efficacy of Rabivac vaccine for animal rabies control in Morocco

PURPOSE: To fight animal rabies, Moroccan veterinary authorities organize annual dog mass vaccination campaigns using Rabivac vaccine, an inactivated adjuvanted cell culture veterinary rabies vaccine. Two experiments were undertaken to assess the efficacy and immunogenicity of Rabivac. MATERIALS AND METHODS: The first experiment involved 13 caged dogs (8 vaccinated and 5 negative controls). Dogs were bled at day 0 (D0) and at days D7, D14, D21, D28, D35, D49, D56, D64, D70, D77, D84, D91, D98, D105, D112, and D119 post-vaccination. At D121, a virulent challenge was performed. After 70 days monitoring period, seven out of eight vaccinated dogs survived the challenge (one dog succumbed to a mesenteric torsion accident) and four out of five controls succumbed. All vaccinated dogs seroconverted and the control dogs remained negative. The second experiment consisted in a field study involving 919 owned dogs randomly selected in eight Moroccan districts located in different parts of the country. The dogs were identified and vaccinated by the parenteral route and bled on the vaccination day (D0) and on D30. RESULTS: Ninety-two percent of dogs developed a positive rabies virus neutralizing antibody response to vaccination and 24% were positive at D0, suggesting that dogs were previously vaccinated. The increase in rabies antibody titers was highly significant in all districts. No significant difference seemed occurring between the geographical status (rural, semiurban, or urban) of the districts on the results obtained. CONCLUSION: Rabivac is efficacious both in experimental and field conditions. This supports its use in dog mass vaccination campaigns.

First trials of oral vaccination with rabies SAG2 dog baits in Morocco

PURPOSE: Canine rabies is a serious health problem in Morocco and about 22 human deaths are reported yearly. Following the World Health Organization (WHO) recommendations, Moroccan authorities evaluated oral rabies vaccine baits specially designed for dogs. MATERIALS AND METHODS: The study was performed in Tiflet area. The vaccine strain was SAG2, a modified live oral rabies vaccine strain. Each bait contained an aluminium/PVC capsule filled with a liquid. Two kinds of baits were used: placebo baits containing methylene blue as a topical marker and vaccine baits containing vaccine suspension. The study was performed according to recommended WHO strategies, i.e., door to door model (DDDM), hand-out and wildlife immunization model (WIM). The DDDM was performed in the rural area of Tiflet on 60 owned dogs. The hand-out strategy was tested on 15 stray dogs. The WIM was performed on 4 transects lines near Tiflet slaughterhouse and near the weekly traditional market location. RESULTS: Using the DDDM, 100% of owned dogs were attracted by the baits and 77% ate the bait. Using the hand-out model, 100% of dogs showed interest in baits and 46.7% took the baits. Using the WIM in stray dogs, up to 73% of baits disappeared and 68% of the capsules containing the SAG2 vaccine were found pierced, depending on the sites of distribution. CONCLUSION: This pilot study showed that baits have a good palatability and that oral vaccination of both owned and stray dogs is feasible with baits specifically developed for dogs and with adapted strategy of distribution.