Abstract:
The immune responses of two S. gallinarum strains, L46 and CN 180, were compared in 15-week-old cockerels. The humoral and cell-mediated immune responses were assayed by means of the indirect haemagglutination test (IHA) and the macrophage migration inhibition test (MIT), respectively. Birds were vaccinated with the two vaccines, respectively, and bled for sera (for IHA) and cells (for MIT) every week up to the seventh week, post vaccination, then every alternate week, three times, and later once every month, for a total period of 37 weeks. Strain L46 was found to induce an immune response that was very similar to that of CN 180. Both gave good humoral and cellular responses.