LMMUNO-SEROLOGICAL STUDIES ON LOCAL AND IMPORTED COMBINED AVIAN VACCINES

Abstract

Fowl cholera (FC) and Newcastle disease virus (NDV) are considered the most important diseases which cause high mortality rates and economic losses among affected birds, so they threaten poultry industry in Egypt. Since long periods, research workers noticed the spread of fowl cholera and Newcastle disease virus (NDV) among young chickens. So it is important to study the possibility of vaccination against both diseases at the same time with use of different vaccines to be used either locally prepared or imported ones and to use live or dead ones to decrease mortality rates. This is fulfilled by challenge test using virulent strains of P. multocida and/or very virulent strains of Newcastle disease virus (V.V.N.D.V.) to chickens vaccinated with fowl cholera and/or Newcastle disease viral (N.D. V.) vaccines and may adopting different programs of vaccination.

1 -- Estimation of immune response against P. multocida was applied

by the following serological tests :• a ) Indirect haemagglutination (IHA) test . b) Enzyme linked immunodorbent assay (ELISA) .