Regarding IgG antibody levels, both the inactivated EBs group and the PmpGs + MOMP group induced higher robust antibodies i.n SEL-10 than the MOMP vaccine i.m on day 28 ( 0.05). further inquiries can Corosolic acid be directed to the corresponding authors. Abstract (infection. We hypothesize that multiple PmpG antigens adjuvanted with ghost (VCG) and chitosan gel might trigger full protection the intranasal route (i.n). In the present study, 40 SPF chickens were randomly divided into four groups, including the PmpGs + MOMP group (i.n), major outer membrane protein (MOMP) group (i.n), PmpGs (Pmp17G + Pmp20G + Pmp21G) group (i.n), and control groups (VCG + chitosan gel) (i.n). Post twice immunizations, the PmpGs + MOMP group yielded highly level-specific IgG, IgA antibodies, and lymphocyte proliferation. As for cytokines, IFN- expression was upregulated Corosolic acid significantly, while IL-10 concentration was downregulated in the PmpGs + MOMP group compared with other groups. Post challenge, exudate inflammations in air sacs, bacterial loads in lungs, and bacterial shedding in throat swabs were reduced significantly in the PmpGs + MOMP group. In the second experiment, 100 breeder ducks were divided into the PmpGs + MOMP group (i.n), the commercial MOMP group (intramuscular injection, i.m), the inactivated EBs group (i.n), and the control group (i.n), 25 ducks per group. Post challenge, the reduced egg production recovered soon in the inactivated EBs group and Corosolic acid the PmpGs + MOMP group. Moreover, the aforementioned two groups induced higher robust IgG antibodies, lymphocyte proliferation, and IFN- secretions than the commercial MOMP vaccine did. Postmortem, lower bacterial loads of spleens were determined in the PmpGs + MOMP group and the inactivated EBs group. However, bacterial clearance of follicular membranes and shedding from the vaginal tract were not significant differences among the three tested groups. Furthermore, the PmpGs + MOMP group induced lower inflammations in the follicles and oviducts. Based on the above evidence, the combination of PmpGs and MOMP adjuvanted with chitosan gel and VCG intranasal route could induce full protection both in the respiratory system and genital tract post infection. More importantly, the combination antigens are superior to the inactivated EBs antigen due to no contamination to the environment and less genital inflammation. The combination of PmpGs + MOMP adjuvanted with VCG and chitosan gel might be a promising novel vaccine by blocking infection from animals to human beings. (is a typical intracellular pathogen that obligately parasitizes in eukaryotic cells. It infects birds, poultry, livestock, and wild animals, causing severe respiratory, reproductive disease, and economic loss as well (1). More important, human psittacosis and mortality cases are reported frequently due to the increasing application of next-generation sequencing, especially the employees or pet hosts closely contacted with pet birds and poultry (2). The latest statistics indicated that 1% of community-acquired pneumonia was triggered by infection (3). Clinical signs are comparable to influenza infection as flu-like fever and human psittacosis are underestimated and ignored due to lack of rapid diagnosis and good treatment (4). Therefore, how to cut Chlamydial transmission from animals to humans is urgently needed in light of public Corosolic acid health implications. Both scientists from veterinary fields and hospital researchers are seeking joint efforts to combat infection. In the past decades, Chlamydia vaccines for animal use have been developed from killed vaccines, live attenuated vaccines, subunit vaccines, live vector vaccines, DNA vaccines to mRNA vaccines (5). As for the vaccines against infection, the first recombinant MOMP vaccine was registered successfully in 2006 and commercialized for broilers in China. After that, the recombinant MOMP vaccine was available for sheep and goats in 2014. Subsequently, the recombinant MOMP vaccines are not recognized due to partial protection for poultry and livestock. Recently, inactivated whole elemental body (EB) adjuvanted with VCG and chitosan induced better protection against infection in SPF.