Immune response to Newcastle disease virus vaccine, fowl-pox vaccine, and Escherichia coli vaccine in Bedouin and White Leghorn chickens.

Immune response to Newcastle disease virus (NDV) vaccine, fowl pox, and E. coli vaccine was compared in the native Bedouin fowl of the Sinai desert, in a commercial Leghorn layer strain, and in the reciprocal crosses between them. Differences were not found in antibody titer levels to attenuated or inactivated NDV vaccines, in the proportion of birds showing post-vaccination immunity to fowl pox, or in the kinetics of postvaccination NDV titer levels. Rate of development of titer to Escherichia coli from day 1 to day 4, however, was significantly more rapid in Bedouin chicks than in the purebred Leghorn or the reciprocal crosses.