Testing of immune-stability of Cap-OMP vaccine stored at room temperature in mice

Abstract

Vaccines are increasingly being used for Salmonella Enteritidis and Salmonella Typhimurium infection. Outer membrane protein (OMP) plays an important role in induction of immune response in the subject against the organism and can be used as an effective candidate vaccine. OMPs are weak antigen; require adjuvants which act non-specifically to increase the immune response of these weak antigens. Calcium phosphate nanoparticles (CAP) have been widely used as adjuvant given to its ease in large scale production and economical. One of the important aspects of vaccination is the proper maintenance of cold-chain that is one of the greatest issues in the developing countries owing to lack of continuous power supply hence, there is a need for stable vaccine against salmonellosis. In the present study, the stability of Salmonella Typhimurium OMP entrapped in calcium phosphate nanoparticle, in terms of immunogenicity, was studied in mice. The CAP-OMP vaccine incubated either for 30 or 60 days in 4○C or 25○C was used to immunize the mice. The CAP-OMP vaccine incubated at 4○C showed significantly higher IgG response than the CAP-OMP vaccine incubated at 25○C. It was observed that CAP-OMP vaccine does not remain stable in room temperature probably due to loss of integrity of antigen that was evident in differential protein band profile in SDS-PAGE.