Oral rabies vaccination of foxes with one or two delayed distributions of SAG2 baits during the spring
During the spring of 1997, various protocols of rabies vaccine bait (SAG2) distribution for foxes were compared: in the first test zone, a first distribution was organised at the end of April, followed by a second distribution two weeks later; in the second test zone, there was a first distribution at the same period as for the previous zone, followed by a second distribution four weeks later, at the end of May. In two control zones, a classical single bait distribution was organised during the
... same periods as for the second distribution in the respective test zones. No statistical differences were observed for adult foxes or fox cubs sampled in the test and control zones neither for baits uptake nor for seroconversion rate. However, seroconversion rates observed in fox cubs population were significantly higher (P < 0.01) in areas vaccinated at the end of May (43 and 56 %) compared with those vaccinated at mid-May (24 and 20%). The vaccinal efficacy of baits was also significantly (P < 0.05) increased for the fox cubs in the areas vaccinated at the end of May (46 and 57%) compared with those vaccinated at mid-May (24 and 25%). This increase in immunological response by fox cubs when vaccinating in late spring must be related to their development. In the early spring, fox cubs are generally too young to have access to baits or to be vaccinated when eating them. For most of these fox cubs, a second distribution will not constitute a booster. Therefore, in order to increase the efficient access of fox cubs to vaccine baits, Spring distribution of baits should preferably be organised during May or June rather than in April. rabies / oral vaccination / fox cub / delayed double bait distribution Resumé -Vaccination orale des renards avec une ou deux distributions successives d'appâts SAG2 au printemps. Lors de la campagne de vaccination orale des renards contre la rage en France au printemps 1997, différents protocoles de distribution des appâts vaccinaux (SAG2) ont été comparés : dans une première zone test, une distribution fin avril suivie d'une seconde deux semaines plus tard à la mi-mai et dans une deuxième zone test, une distribution fin avril suivie d'une seconde, Vet.