[Production and titration of a vaccine against the infectious encephalomyelitis of poultry].

A vaccine was produced against infectious encephalomyelitis of day-old chicks infected cerebrally with strain Calnek 1143. It is a brain suspension from killed birds that have shown disease symptoms, treated with penicillin and streptomycin and stored at -20 degrees C. Experiments were carried out to titrate the vaccine through determining the minimum infective dose for day-old chicks treated with 0.

[Combined vaccination of birds with inactivated and live vaccines].

Studies were carried out on the immune response of birds-parental forms of broilers--in the combined use of an inactivated vaccine Dessau and a live avirulent vaccine La Sota. The dynamics was followed up till the age of 58 weeks of the changes taking place at an antidody level, and the resistance of the birds after challenging with a virulent virus. After the first immunization with a killed vaccine there was an average geometric titer of 78.

[Effect of the preparation hydroprot on immunogenesis in birds with Newcastle disease].

Investigations were carried out on the immunogenesis and the serum-protein profile in the treatment of broilers with the protein hydrolysate Hydroprot as well as with Newcastle disease vaccine. The treatment with Hydroprot led to a lower average geometric titer of antibodies--6.4 on the 14th, 6.

[Properties of the contagious ecthyma virus used for vaccine production].

Experiments were carried out to establish the effect of some antibiotics and merthiolate on the vaccinal Phylaxia strain of ecthyma contagiosa. Besides, followed up was the effect of these antibiotics on concomitant microflora that had multipled in the virus suspension. Trials were also made to titrate the vaccinal strain on lambs through scarification.