The current study aimed to investigate the effects of different vaccination programs against 
Newcastle disease (ND) on both immune response and some blood parameters in local 
chickens in Shirqat city. Ninety local chicks were divided into three groups, 30 chicks each. 
The first group (G1) left unvaccinated, while the second and third groups (G2, G3) were 
vaccinated with ND strains using different methods of administration. A significant decrease 
was recorded in both the number of red blood cells (RBCs), white blood cells (WBCs) and 
packed cell volume (PCV) in G3 at 14 days of age. Additionally, a significant decrease in 
antibody levels in the G2 at 24 days of age. A significant decrease was also noted in both the 
number of RBCs in the G2 and the hemoglobin in both G2 and G3. A significant decrease in 
both PCV and mean corpuscular hemoglobin concentration (MCHC) was recorded in the G3.
Furthermore, a significant decrease in antibody levels was observed in both the ELISA and 
hemagglutination inhibition (HI) tests in G3, along with a significant difference in the number 
of RBCs in G2 and G3. There was also a significant difference in hemoglobin and PCV levels 
in G3 at 34 days, and a significant decrease in PCV value was noted in G3 at 42 days. In 
conclusion, the different vaccination programs against Newcastle disease led to a significant 
decrease in antibody levels in the second and third groups at 24, 34, and 42 days of age. The 
study also revealed that some blood parameters in the vaccinated groups showed a significant 
decrease at the level of P ≤ 0.05