Memoirs of the Department of Agriculture in India (Veterinary Series) Studies in Rinderpest September 1922

The duration of the immunity conferred by serum alone . 105 (a) The wide divergence in the views held as to the duration of the immunity . ib. [...] The above figure shows an important set of statistics in the form of a graph and from these it is apparent that the serum alone method of inoculation is a long way short of efficient for the control of rinderpest. [...] This factor combined with the use of an insufficient dosage for the susceptibility of the animals dealt with has led to a great deal of the disappointment which has been reported_in the field. "TOOL AND DOYLE 10'7 (b) CONDITIONS WHICH MUST BE FULFILLED WHEN TESTING THE DURATION OF THE IMMUNITY CONFERRED BY SERUM ALONE. [...] A close examination of their experiments shows that an accurate estima- tion of the results was vitiated in each case by an insufficient knowledge of the potency of the serum they were using or in other words of the minimum dose of serum which was necessary to save the life of the animals with which they were experimenting. [...] In a herd of cattle of low susceptibility such as most of the plains cattle of India, the spread of the disease is often very slow and the infection is probably kept alive by chronic bowel cases which are capable of spreading it for a period far in excess of the duration of the serum immunity.