EXPERIENCES ON THE ORAL VACCINATION OF FO XES AGAINST RABIES IN HUNGARY

The first Hungarian oral vaccination campaign against fox rabies was c arried out in a 25 to 50 km wide vaccination cordon along the Austrian border in Gyor-Moson-Sopron, Vas and Zala counties in October 19-26, 1992 (Figure 3). 80 000 doses of vaccine baits containing SAD B19 atte nuated rabies live vaccine virus (Fuchsoral ad us, vet., Klocke Pharma -Service GmbH, Weingarten/Baden, Germany) were used covering an area o f approx. 500 000 hectares. The distribution was executed manually in squares by two AN-2 type agricultural airplanes, through a tube (Figur e I) inserted in the whole perforated in the bottom of aircraft. The a ircraft was equipped with a satellite navigation system (GPS, General Positioning System, Figure 2). This made possible the exact distributi on of 16 baits/km(2) with equal distances of 250 m (+/-10 m). The camp aign was carried out without any problem and accident. The brain of al l wild and domestic animal cadavers found in the vaccination area were investigated for rabies. The type of rabies virus was identified by t hree monoclonal antibodies (MAB1=W239.17, MAB2 = W187.5 and MAB3 = W18 7.6.1.). All the virus strains originated from the vaccination area pr oved to be street virus (Tables 1 and 2). Between November 15, 1992 an d January 15, 1993, a total of 58 foxes were shot to control the effic acy of the oral immunization. 68.2% of the body fluids of foxes contai ned antibodies in a dilution of 1:60 or higher (Figure 4) and tetracyc line marker could be demonstrated in 63.8% of fox teeth (Figure 5). As a result of vaccinations, the incidence of rabies cases decreased sig nificantly in the vaccination area, as compared to the first quarter o f 1992 (Figures 6 and 7). The vaccination campaign was repeated in Apr il and October, 1993. However, the vaccinated area was 600 000 her,tar es. Oral vaccination of foxes is going to be carried out in the spring and autumn of next years, as well, gradually extending the vaccinatio n area towards the Eastern part of Hungary.