Freeze-drying of Aegyptianella pullorum.

Heparinized whole blood, parasitized with Aegyptianella pullorum, was collected from 2 fowls. Buffered lactose peptone (BLP) was added v/v as a stabilizer and the mixture lyophilized in 2 ml aliquots after rapid or slow freezing. At different stages during the freeze-drying process, as well as after lyophilization and reconstitution with 1.8 ml of sterile water, samples were taken and injected into pullets. Infectivity was maintained throughout. However, the prepatent period was lengthened after freezing and particularly after lyophilization when there was some loss of viability.

Comparison of oil adjuvant and aluminium phosphate-adsorbed toxoid for the passive immunization of lambs against tetanus.

Immunization of ewes with oil emulsion toxoid followed by an aluminium phosphate-adsorbed toxoid both containing 10 Lf per dose, resulted in a very high antitoxin level in their lambs. Two injections of aluminium phosphate-adsorbed toxoid also imparted a passive immunity to lambs which is considered to be adequate to protect them against tetanus for 4 weeks after birth.