IMMUNOLOGICAL RESPONSES OF MAMMALIAN HOST AGAINST TAPEWORM INFECTIONS .I. SPECIES SPECIFICITY OF HEXACANTH EMBRYOS IN PROTECTING SHEEP AGAINST TAENIA HYDATIGENA

  • 1 January 1964
    • journal article
    • research article
    • Vol. 7  (5) , 489-+
Abstract
Ninety sheep, comprising three groups each of thirty animals, were vaccinated intramuscularly with the eggs or activated embryos of Taenia hydatigena, T. ovis or T. pisifor-mis, together with ten controls, were subsequently challenged with eggs of T. hydatigena. Each of these three groups of thirty animals were subdivided into three subgroups of ten animals. In the ten animals comprising the first sub-group in each group, the vaccine was injected as activated embryos, in those comprising the second sub-group as viable eggs and in those of the third sub-group as eggs which had been killed by deep-freezing at [long dash]70[degree]. The ten sheep injected with activated embryos of T. hydatigena developed a solid immunity to the establishment of the challenge infection. None of the ten sheep injected with viable eggs of T. hydatigens developed a solid resistance to the extablishment of some cysticerci from the challenge dose of eggs of T. hydatigena, but eight of the ten animals in this sub-group resisted the subsequent growth of the cysticerci to the infective stage. In the remaining two sheep only one cysticercus reached maturity in each animal. None of the sheep injected with the activated embryos of T. ovis or T. pisiformis developed a solid resistance to the establishment of the challenge infection with T. hydatigena, but most of those animals injected with the activated embryos of the former and some of those injected with those of the latter cestode developed a solid resistance to the log- term survival of the challenge infection with T. hydatigena. No significant resistance was observed either to the establishment or to the subsequent growth of the challenge infection of T. hydatigena in those sheep previously injected with either killed eggs of T. hydatigena or viable or killed eggs of T. ovis or those of T. pisiformis.