Evaluation of innate immune responses to Newcastle disease vaccines in broiler chicken

Adaptive immune response in broiler chicken varies against each type of Newcastle disease virus (NDV) vaccine. These variations could be explained by the observed differences in the level of humoral and cell components of adaptive immunity during inflammation and acute phase response. A total of 150 day-old Ross 308 broiler chicks were randomly assigned into the five treatment groups. First group was intramuscularly vaccinated with inactivated Lasota strain of ND, the second and the third groups vaccinated with Vitapest and Lasota by intraocular route. Two groups kept as the controls only received PBS by intramuscular and intraocular routes. Blood sample was taken before vaccination and two consecutive days after vaccination. Serum amyloid A (SAA) and alpha-1 Acid glycoprotein (AGP) were measured by ELISA kits for chicken acute phase proteins. White blood cell count and the ratio of heterophils to lymphocytes were measured as indicator of stress. The results indicated that injection of the vaccine increased the acute phase protein (SAA) and caused stress in treatment groups but no significant change in AGP level. Inactivated ND vaccine had the highest effects on adaptive immunity which also caused monocytosis and mild basopenia in white blood cells. By identifying the effects of each vaccine on adaptive immunity, it is possible to decide on the proper vaccine required for each flock. Understanding the significant effects of vaccines on the level of acute phase proteins and stress could be used for vaccine design the vaccine and poultry flock managements.