|Dudnikov, Leonid - NARVAC - MOSCOW RUSSIA|
Submitted to: International Marek's Disease Symposium Abstracts and Proceedings
Publication Type: Proceedings
Publication Acceptance Date: October 9, 2000
Publication Date: N/A
Technical Abstract: Vaccines against Marek's disease (MD) have historically been prepared from viral strains biologically and, in some cases serologically, distant from the field strains that provide the natural challenge. Although these heterologous vaccines have been effective, it is possible that vaccines prepared from closely related or autologous serotype 1 strains would be advantageous. To test this hypothesis, chickens were vaccinated at hatch with three different serotype 1 MD vaccine strains, R2/23, 584A/70 and 648A/100, each attenuated by passage in cell culture and determined to provide significant protection against virulent challenge. Vaccines were considered to be autologous to the low passage virus of the same strain and heterologous to low passage viruses of other strains. Data from 3 replicate trials showed that all three vaccines provided high levels of protection against each challenge virus. The highest level of protection (mean 82%) was against Md11 challenge and the lowest (69%) level was against 648A challenge. However, no consistent differences were noted in protection by autologous and heterologous vaccines against the same challenge virus.