Vaccination of Chickens with Mycoplasma gallisepticum

MYCOPLASMA GALLISEPTICUM infection, both natl ural and experimental, produces demonstrable immunity both in chickens2,10,11,12,13,15,16 and in turkeys.4',6,712 Similarly, willful infection or vaccination with M. gallisepticum has induced varying degrees of immunity in chickens1,3'9 and turkeys. ,14 In general, it appears that at least a moderate degree of transient immunity develops in both species of fowl; however, the immunity produced in turkeys seems to be of a lower grade and is somewhat more transient than that produced in chickens. Much information has been reported on the immune response to M. gallisepticum, but the relatively few individuals studied and the diversity of methods used indicate a further need for experiment in this area. The experiments reported herein were designed to provide additional information on the immune response induced in both mature and immature chickens by M. gallisepticum vaccination.