2
Rinderpest Immunisation with Goat Virus
goat virus alone showed a slight drop in milk yield. There was no case
of a pregnant cow aborting as a result of the goat virus although a number
were inoculated when over seven months in calf. Buffaloes reacted more
strongly than cattle, the attempt to control this by giving half the dose seems
to have had an appreciable effect. The effect of work on buffaloes after
inoculation was stated to enhance the reaction, but this does not appear to
apply to ' plains ' buffaloes, and in bullocks it seems to have no ill effect.
He concludes by saying that the results far exceeded expectations ; 100,000
animals have been inoculated by this method and after eliminating those
animals which were obviously inoculated during the incubation period the
loss worked out at half a per cent. Bachan Singh [1939] states that the reaction
in the case of tissue virus (i.e. spleen) is milder than that of blood virus both
in cattle and buffaloes and in old animals it is usually imperceptible. ' In
such cases the duration of immunity is bound to be of short interval, which
is decidedly a disadvantage of tissue virus when compared with blood virus
which on account of its potent nature of reaction confers a more lasting
immunity.'
Among his conclusions are noted:—A fixed virus from
Mukteswar possesses a low virulence for cattle of indigenous breeds. Blood
virus has been found to be safe for local-bred buffaloes of this province
(Central Provinces and Berar, India). The longest period of immunity
tested so far was three-and-a-half years in the case of blood virus and it
is anticipated that it would be potent for longer periods. If extensive in-
oculations are carried out in an area on a prophylactic basis, the chances of
spread from vaccinated animals to non-vaccinated animals are very remote.
In contrast to these views, however, the Annual Report of the Madras
Civil Veterinary Department for 1938-39 states ' It was also found that positive
reactions to the vaccinations could set up fresh foci of infection and this was
proved by the subinoculated animals developing rinderpest' and a further
quotation from the same report on the same subject is ' The goat virus alone
method which has been favourably reported on in other provinces was also
carried out in small areas. A wide use of this method was not advocated
as it has been discredited as it produces undesirable reactions and other
bad effects after vaccination. At present serum simultaneous inoculation
with goat virus is giving excellent results as an outbreak stopper.' Again
D'Costa [1938] says that goat virus causes a 70 per cent mortality in hill
bulls and can be used alone for immunisation only on cattle which have a
high degree of resistance to rinderpest.
In Burma, inoculations with goat virus alone have been widely employed
and the Annual Report of the Civil Veterinary Department for 1938 shows
that 549,564 animals were inoculated during the year ; indeed this method
appears to have become the routine one for rinderpest control in that'
country. It is due to Pfaff [1939] that the production of desiccated goat
spleen has been put on a practical basis and the advantages of this more
stable and reliable product are manifest. This author also states that
repeated attempts to transmit the disease to cattle by contact failed and
field observations support these findings. With buffaloes the position is a
little uncertain and the spread of disease to uninoculated buffaloes by
contact with inoculated buffaloes has been reported.