biostudies-literatureZuo ZNatural Science Foundation of Beijing MunicipalityNational Natural Science Foundation of China10389https://www.ebi.ac.uk/biostudies/studies/S-EPMC8129140biostudies-literatureUnknown11(1)Vaccines based on live attenuated Chlamydia elementary bodies (EBs) can cause disease in vaccinated animals and the comparably safer inactivated whole EBs are only marginally protective. Recent studies show that a vaccine formulation comprising UV-inactivated EBs (EB) and appropriate mucosal delivery systems and/or adjuvants induced significant protective immunity. We tested the hypothesis that intranasal delivery of UV-inactivated C. psittaci EB formulated in Vibrio cholerae ghosts (VCG)-chitosan nanoparticles will induce protective immunity against intranasal challenge in SPF chickens. We first compared the impact of VCG and CpG adjuvants on protective immunity following IN mucosal and IM systemic delivery of EB formulated in chitosan hydrogel/microspheres. Immunologic analysis revealed Scientific reportsIntranasal immunization with inactivated chlamydial elementary bodies formulated in VCG-chitosan nanoparticles induces robust immunity against intranasal Chlamydia psittaci challenge.PMC8129140No.31672517No.6172019Zou YWu JHe CZhang TZuo ZGuo YEko FOLi QfalseIntranasal immunization with inactivated chlamydial elementary bodies formulated in VCG-chitosan nanoparticles induces robust immunity against intranasal Chlamydia psittaci challenge.Vaccines based on live attenuated Chlamydia elementary bodies (EBs) can cause disease in vaccinated animals and the comparably safer inactivated whole EBs are only marginally protective. Recent studies show that a vaccine formulation comprising UV-inactivated EBs (EB) and appropriate mucosal delivery systems and/or adjuvants induced significant protective immunity. We tested the hypothesis that intranasal delivery of UV-inactivated C. psittaci EB formulated in Vibrio cholerae ghosts (VCG)-chitosan nanoparticles will induce protective immunity against intranasal challenge in SPF chickens. We first compared the impact of VCG and CpG adjuvants on protective immunity following IN mucosal and IM systemic delivery of EB formulated in chitosan hydrogel/microspheres. Immunologic analysis revealed 2021-01-01T00:00:00Z2021 May2025-04-05T14:33:46.545Z2025-04-05T14:33:46.545ZS-EPMC81291403400198810.1038/s41598-021-89940-8