Papers andArticles Effectiveness ofSAGIoral vaccine forthelong-term protection ofredfoxes (Vulpes vulpes)against rabies

SAG]vaccine Threegroups of10foxes werevaccinated bythedirect oral instillation of2mlofSAG1rabies virus vaccine containing 106 MICLD50 (107 TCID50/ml) infectious viral particles/ml. SAG1isa natural variant oftheattenuated rabies vaccine strain SAD Bernandwasselected inthepresence ofmonoclonal antibodies. Thestrain isdevoid ofresidual pathogenicity forthefox andthehighly susceptible adult laboratory mousebytheoral, intramuscular andintracerebral routes. The foxeswere challenged six, 12and18monthslater withavirulent vulpine street rabies virus (GS7-1-1). Theyallsurvived, whereas seven ofeight unvaccinated control foxes died. THE success achieved inthecontrol ofrabies inEurope bythe oralvaccination offoxes waspreceded bythedevelopment of several innocuous andefficacious vaccines withminimal potential risk fortheenvironment. Theselection oflowvirulence variants oftheattenuated vaccine strain SADBern, occasionally called 'apathogenic mutants', madethis vaccine possible. Oneofthese variants, SAGI(for SADGifsurYvette), wasobtained bytheselectionofnatural mutants underthepressure ofrabies-specific monoclonal antibodies (Flamand andothers 1993) andproved to beefficacious forfoxeswhenadministered either directly by mouthorbybait. Toensure thesuccess oforal vaccination campaigns infoxes itisessential that asingle vaccine doseprovides a protective immuneresponse fortheaverage life ofafoxinthe field (Artois andAubert 1982, Artois andothers 1993). Forthis reason theprotection conferred byasingle oral doseofSAGIvaccineinthered fox (Vulpes vulpes) wasstudied forupto18 months.