Investigation of Immunization of DNA-Based Polyepitop HIV Vaccine Candidate in Mouse Model and the Impact of Alum Adjuvant and Subcutaneous Infusion on its Efficiency

One of the challenges of today's world and also global health priorities is pandemicity of AIDS. Studies have shown that the scope and breadth of the immune responses induction are very effective to protect against HIV. Moreover, simultaneous induction of humoral and cellular immunity responses increases the effectiveness of candidate HIV vaccines. Hence, new approaches such as polyepitopic vaccine strategy and addition of different adjuvants in HIV vaccines’ formulations have been recently considered. In the present study, eukaryotic expression vector (pcDNA3.1-tat/pol/gag/env) was transformed and amplified in the prokaryotic host cells E. coli (DH5α). After vector extraction, it was concentrated and formulated alone and in combination with Alum adjuvant and used as DNA candidate vaccines. DNA candidate vaccines were, then, subcutaneously injected to the BALB/c mice on 0, 14, and 28 days and elicited humoral and cellular immunity responses were finally evaluated. The results showed that the candidate DNA vaccine could not efficiently induce immunity responses (both humoral and cellular responses) by subcutaneous route injection. This observation can be due to a defect in each of the steps of vector harvesting by the target cell to express the surface presentation of the epitopes on the one hand, or the inefficiency of the subcutaneous injection method on the other. Therefore, other vaccines’ injection and deliveries routes along with addition of other adjuvants in vaccine’s formulations could induce immunity responses efficiently and increase vaccine efficacy.