Evaluation of cell culture propagated and in vivo propagated hemorrhagic enteritis vaccines in turkeys.
The immune response of turkeys to a liquid, was compared with a previously frozen, cell culture propagated hemorrhagic enteritis (HE) vaccine. The liquid cell culture propagated HE vaccine was able to induce 100% seroconversion in turkeys 4 weeks after being vaccinated at 3.5 weeks of age; however, the previously frozen cell culture propagated HE vaccine induced 80% seroconversion 4 weeks post vaccination (P < 0.05). The average seroconversion in turkey flocks administered the liquid cell culture propagated HE was 97% in comparison with 98.5% in flocks given the splenic vaccine (P > 0.05). The complete absence of HE antigens in spleens of birds 5 days after being challenged with the virulent HE virus (40,000 TCID50 per bird) at an age of 9.5 weeks, was used as a model for successful protection against HE disease. The HE antigens were absent from spleens of all challenged birds that were previously vaccinated by the liquid cell culture propagated HE vaccine or splenic vaccine.
Department of Research and Development, Brinton Laboratories, Willmar, MN 56201.
E K
EK
Barbour
P E
PE
Poss
M K
MK
Brinton
J B
JB
Johnson
N H
NH
Nabbut
D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis*; D000956:Antigens, Viral / Q000276:immunology; D002478:Cells, Cultured; D004752:Coronavirus, Turkey / Q000276:immunology*; D004753:Enteritis, Transmissible, of Turkeys / Q000276:immunology* / Q000517:prevention & control; D004797:Enzyme-Linked Immunosorbent Assay; D005069:Evaluation Studies as Topic; D007109:Immunity; D014422:Turkeys; D014765:Viral Vaccines / Q000276:immunology*
D000914:Antibodies, Viral; D000956:Antigens, Viral; D014765:Viral Vaccines