Preparation and immunological response to a new mixed vaccine composed of inactivated Newcastle disease virus, inactivated infectious bronchitis virus, and inactivated Hemophilus gallinarum [Chickens]

A new inactivated mixed vaccine of Newcastle disease virus (NDV), infectious bronchitis virus (IBV), and Hemophilus gallinarum (HG) was prepared. Immunological response to the new vaccine was determined by inoculation of susceptible birds. Demonstrated in all vaccinated birds were a sufficient increase of NDV hemagglutination-inhibition (HI), HG HI, and IB neutralization antibody titers, and development of resistance to challenge by NDV and HG. HG HI antibody titer was correlated with protection against infection by HG 221 strain.