A field trial of fox vaccination against rabies using a vaccinia-rabies recombinant virus was carried out in Belgium on October 24, 1987. Each vaccine capsule contained a suspension of 10(8) TCID50 of the recombinant virus and was introduced into a chicken head. Each chicken head contained 150 mg of tetracycline as a marker of uptake. Two hundred and fifty heads were distributed in an area of 6 km2 situated within a military zone. The bait uptake was monitored for 15 days after the distribution. Sixty-three per cent of the chicken heads were taken by wild animals within that period. The trial was controlled according to the rules defined by the World Health Organisation.

No abstract

Following the success of the JP15 scheme and subsequent annual vaccination campaigns, East Africa was virtually free of rinderpest after the mid 1960s and the disease was considered beaten. However, economic difficulties have recently reduced the expensively maintained vaccine cover and the disease has reappeared throughout much of the region. In 1979 rinderpest was diagnosed in cattle in north eastern Uganda and caused considerable losses until finally brought under control in 1981. No field outbreaks of the disease in cattle have been seen in Kenya but there is serological evidence that the virus has recently infected unvaccinated sheep and goats and wild ungulates in that country. In 1982 rinderpest was confirmed in the laboratory as the cause of death of large numbers of buffaloes in northern Tanzania and implicated as the cause of a rinderpest-like disease of cattle which is reported to be still active in that area. Substantial aid is essential for further control and research if the virus is not again to become endemic in the region.

No abstract

Five groups of Tswana-cross castrated male cattle between 20 and 30 months of age (a total of 158 animals) were transported from a ranch in a heartwater-free area of south Botswana to a feedlot near Gaborone in the east of Botswana where heartwater is endemic. On arrival, one group was vaccinated intravenously with the Onderstepoort sheep blood heartwater vaccine, one group was vaccinated intravenously with the new Onderstepoort tick-derived heartwater vaccine and a third group was vaccinated subcutaneously with this tick-derived vaccine. Vaccine reactions were blocked with long acting oxytetracycline on the first day of fever. A fourth group had a series of injections of long acting oxytetracycline on days 0, 7, 14 and 21 after arrival, and a fifth served as untreated controls. The animals remained at the feedlot for 65 days during which time they faced a low level of challenge by Amblyomma hebraeum ticks. None contracted heartwater and so they were then challenged, together with a further group of control cattle, with a dose of the sheep blood vaccine. Some animals in all groups had severe heartwater reactions and died despite therapy, but 76.7 per cent, 64.5 per cent and 74.3 per cent of the cattle in the blood vaccine, intravenous tick vaccine and long acting oxytetracycline groups respectively were resistant to challenge, compared with 48.3 per cent of the subcutaneous tick vaccine group and 36.4 per cent of the controls. It was concluded that intravenous vaccination of susceptible adult cattle with either the blood or the tick-derived vaccine needs careful monitoring in the month after vaccination and does not necessarily result in immune animals.(ABSTRACT TRUNCATED AT 250 WORDS)