2026-04-13T06:45:57Zhttps://recercat.cat/oai/request

oai:recercat.cat:10256/255052025-03-15T04:05:45Zcom_2072_452955com_2072_2054col_2072_453069

00925njm 22002777a 4500 dc Livingstone, Morag author Aitchison, Kevin author Palarea Albaladejo, Javier author Chianini, Francesca author Rocchi, Mara Silvia author Gastón Caspe, Sergio author Underwood, Clare author Flockhart, Allen author Wheelhouse, Nicholas author Entrican, Gary author Wattegedera, Sean Ranjan author Longbottom, David author 2024-10-17 Chlamydia abortus causes the disease ovine enzootic abortion, which is one of the most infectious causes of foetal death in small ruminants worldwide. While the disease can be controlled using live and inactivated commercial vaccines, there is scope for improvements in safety for both sheep and human handlers of the vaccines. We have previously reported the development of a new prototype vaccine based on a detergent-extracted outer membrane protein preparation of C. abortus that was determined to be more efficacious and safer than the commercial vaccines when administered in two inoculations three weeks apart. In this new study, we have developed this vaccine further by comparing its efficacy when delivered in one or two (1 × 20 µg and 2 × 10 µg) doses, as well as also comparing the effect of reducing the antigen content of the vaccine by 50% (2 × 5 µg and 1 × 10 µg). All vaccine formulations performed well in comparison to the unvaccinated challenge control group, with no significant differences observed between vaccine groups, demonstrating that the vaccine can be administered as a single inoculation and at a lower dose without compromising efficacy. Future studies should focus on further defining the optimal antigen dose to increase the commercial viability of the vaccine Ovelles -- Vacunació Sheep -- Vaccination Ovelles -- Patògens Sheep -- Pathogens Bacteris patògens Pathogenic bacteria Evaluation of the Protective Efficacy of Different Doses of a Chlamydia abortus Subcellular Vaccine in a Pregnant Sheep Challenge Model for Ovine Enzootic Abortion