Evaluation of Four Adjuvant Combinations, IVAX-1, IVAX-2, CpG-1826+Montanide ISA 720 VG and CpG-1018+Montanide ISA 720 VG, for Safety and for Their Ability to Elicit Protective Immune Responses in Mice against a Respiratory Challenge with Chlamydia muridarum

There is an urgent need to produce a vaccine for Chlamydia trachomatis infections. Here, using the muridarum major outer membrane protein (MOMP) as antigen, four adjuvant combinations IVAX-1 (MPLA+CpG-1018+AddaVax), IVAX-2 (MPLA+CpG-1018+AS03), CpG-1826+Montanide ISA 720 VG (CpG-1826+Mont) and CpG-1018+Montanide (CpG-1018+Mont), were tested their local reactogenicity ability elicit protection in BALB/c mice against respiratory challenge with C. muridarum. Immunization or induced no significant following intramuscular immunization. In contrast, vaccines containing Montanide resulted formation of granuloma. Based on IgG2a/IgG1 ratio serum, elicited Th1-biased responses. highest vitro neutralization titers while CpG-1018+Mont stimulated lowest. As determined by levels IFN-γ produced T-cells, most robust cellular immune responses immunized CpG-1018+Mont, weakest mounted receiving IVAX-1. Following challenge, lost least amount body weight had lowest number inclusion-forming units (IFUs) lungs, those IFUs lungs. Animals vaccinated CpG-1826+Mont lightest lungs heaviest. To conclude, due safety adjuvanticity, IVAX formulations should be considered inclusion human Chlamydia.