106 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [VII.

                           PREPARATION OF VACCINE

Both the blood and tissue vaccines employed at the farm for the immunisation
of cattle were supplied by the Pathological Section of the Punjab Veterinary
College, Lahore.

The attenuated goat virus employed at the Punjab Veterinary College for
the purpose of manufacturing blood and tissue vaccine, was obtained from the
Imperial Institute of Veterinary Research, Muktesar, about 2 years back and
maintained by continuous passage in local bred goats.

The blood virus issued for use at the farm was 24 to 48 hours old. It was
supplied in the form of whole blood mixed with equal parts of 1 per cent sodium
citrate solution. The dose of the citrated solution of goat blood virus was 2
c. c. per head.

The goat tissue virus used at the farm was about 1 to 15 days old. It was
despatched from the Lahore College in ampoules each containing one gramme
piece of spleen tissue.

The maceration and dilution of vaccine was carried out at the farm according
to the instructions issued by the Imperial Institute of Veterinary Research,
Muktesar.

Each one gramme piece of spleen was macerated in 100 c.c. of normal saline
solution and used in 1 c. c. dose per animal. The blood and tissue vaccines were
despatched from the College, per passenger train, packed in ice and saw dust.

During the course of these inoculations it was sometimes necessary to keep
a quantity of tissue vaccine over-night. In such instances the material was kept
in a cool dark place packed in a large quantity of ice.

                                CHOICE OF THE VIRUS

The choice between the two types of virus is very difficult. It is not yet
definitely ascertained that a febrile reaction is necessary for conferring lasting
immunity. But, if immunity is assured only when the animal body reacts to the
vaccine, then there is no doubt that blood vaccine is definitely better than the
tissue vaccine. If, however, this is not essential, then there is no doubt that the
tissue vaccine is to be preferred in the field inoculation work. It is easy of applica
tion in the field, its cost of production is extremely low ; its distribution is inexpen
sive, and its longer viability in storage is its greatest outstanding feature.

Kerr and Menon [1934] in their note regarding the use of goat virus as a means
of controlling rinderpest outbreaks observe that goat blood vaccine was not
suitable for general application in the field as it necessitated the presence of more
experienced officers to control the operations. Besides, it was impracticable to
maintain at headquarters, a large stock of potent goat blood vaccine. On the
other hand, the goat tissue vaccine was easily prepared and preserved in sealed
ampoules which were quite handy for packing and despatch by post. Moreover,