Introduction Chlamydia trachomatis, an obligate intracellular parasite, is a major cause of genital infections in human. The pathogen is sexually transmitted and responsible for serious reproductive and other health problems. Despite the availability of antibiotic therapy, infection rates are increasing worldwide. This is mainly due to the asymptomatic nature of most infections and the lack of effective screening programs. Vaccination is therefore considered to provide the best means of controlling chlamydial infection. Attempts to vaccinate with whole-cell vaccine or with purified chlamydial proteins eliciting CD4⁺ T cells and/or antibodies have failed as they provide only partial protection in animal models. Thus, identification of protective antigens that could be used either as an alternative to those already characterised or in combination with them is a high priority in chlamydial vaccine development.

Methods We used “Reverse Vaccinology” approach using available bioinformatics tools to identify chlamydial proteins eliciting humoral and/or cell-mediated immunity and selected effective antigen vaccine combinations.

Results Reverse vaccinology technique has helped us to identify putative antigens that could serve as vaccine candidates for different strains of C. trachomatis, prevalent in India. This approach has led to the identification of novel and highly conserved protein antigens that are either secreted or expressed on the bacterial surface and demonstrate protection in silico. Notably, each of these identified putative antigens, can be produced as a soluble recombinant protein in Escherichia coli, a property that is a considerable asset for the commercial production of a vaccine. The Reverse vaccinology approach thus could help reduce the time and cost required for the identification of novel and suitable antigen candidates and subsequent vaccine production.

Conclusion The successful integration of genome screening method, coupled with the use of various bioinformatics tools has facilitated us to identify better vaccine candidates.

Disclosure of interest statement No conflict interest.