A single dose of alum-precipitated epsilon toxoid (APT) produces only a transitory immunity when given to fully susceptible sheep. A maximal immunity response is brought about by two injections each containing 90 Lf toxoid. The interval between the primary and secondary stimuli may vary from two to six weeks without influencing the end result.
The journals have been scanned in colour with a HP 5590 scanner; 600 dpi. Adobe Acrobat v.11 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.