Skip to main content

Table 4 Protective efficacy of the rMDV-S1 virus against MDV RB1B challenge

From: Protection conferred by a recombinant Marek’s disease virus that expresses the spike protein from infectious bronchitis virus in specific pathogen-free chicken

Groups Clinical signs Mortality Gross lesions Histopathological lesions PI (%)
rMDV-S1 - 0% (0/20) 0% (0/20) 0% (0/20) 100
CVI988/Rispens - 0% (0/20) 0% (0/20) 0% (0/20) 100
control + 90% (18/20) 95% (19/20) 100% (20/20)  
  1. Note: One-day-old SPF chickens were vaccinated with either the rMDV-S1 or CVI988/Rispens virus and challenged 7 days later with the MDV RB1B strain. Clinical signs and mortality were observed for 6 weeks, and the chickens that died during challenge and those that were euthanized at the end of the observation period were necropsied and subjected to gross and histopathological examination. Chickens with gross tumor lesions were considered positive for histopathological lesions.