@conference {41559,
	title = {Immunity in pregnant ewes following a live-dead vaccination and infection with Salmonella Brandenburg},
	booktitle = {Proceedings of the New Zealand Society of Animal Production},
	volume = {65},
	year = {2005},
	month = {Jan},
	pages = {157-162},
	publisher = {New Zealand Society of Animal Production},
	organization = {New Zealand Society of Animal Production},
	address = {Christchurch},
	abstract = {  The aim of this study was to investigate the efficacy of a combined live{\textendash}dead vaccination protocol to protect sheep  against  Salmonella  Brandenburg infection. Thirty ewes were randomly divided into two groups, one of which was  vaccinated and the other acted as a control. The vaccinated group received a live modified  Salmonella  Typhimurium  vaccine (given by eye-drop) followed 4 weeks later by a sub-unit preparation derived from  S. Brandenburg (given  subcutaneously with the adjuvant Quil A). Following challenge with wild type S. Brandenburg (4 weeks after the booster),  43\% of the ewes aborted in the vaccine group as compared with 53\% of the controls. However, a higher mortality rate was  found in the vaccine group (43\% vs 20\%). Using an enrichment/selection procedure,  S. Brandenburg was detected in the  faeces of all challenged animals until 3 weeks post challenge. By 6 weeks and 9 weeks post challenge approximately 50\%  and 30\% of animals respectively were shedding, irrespective of treatment. Following administration of the live primary and  subunit (secondary) vaccines, levels of total IgG, IgG1 and IgM antibody (measured with an indirect ELISA) were  significantly increased in comparison with the control group (P < 0.01). The cell-mediated immune response (interferon  gamma from whole blood cultures) was also enhanced following use of the live attenuated vaccine (P < 0.01), but was much  less pronounced after boosting with the subunit vaccine and following challenge. In summary, vaccination evoked immune  responses but did not give protection to experimental infection with S. Brandenburg.},
	issn = {1176-5283},
	author = {Li H and McFarlane RG and Amoafo OY and Zhang XZ}
}
