Hepatitis C Virus Genotype 1b Vaccine can Benefit Egyptians, where Genotype 4a prevails (105.39)

Abstract Hepatitis C Virus (HCV) infection is a global health burden specially in Egypt, where HCV genotype 4a predominates. Control of HCV infection will remain a challenge until the development of an effective vaccine that protects against different genotypes. There are several HCV genotype 1 vaccines in the pipelines. Differences in antigenic structure among genotypes could make cross protection against other genotypes unlikely. To assess whether Egyptians can benefit from genotype 1-based vaccines, HCV-specific T cell responses were examined in 37 HCV genotype 4a-infected patients using an interferon gamma (IFNγ) ELISpot assay in response to 7 HCV overlapping 15mer peptide pools derived from both genotype 1b and 4a that cover most of the HCV genome. Twenty two (59%) and 16 (43%) subjects responded to at least one peptide pool derived from genotype 1b and 4a, respectively, with 39% exact match in responses. Importantly, responses in different genome segments showed ≥55% exact match in response to the pools tested except the NS5a region (25%). The average IFNγ total spot forming cells (SFC)/106 PBMC (+SE) in the responding subjects for genotype 1b and 4a was 484±89 and 544±77, respectively (p=0.6). There was no significant differences in the responses of those who resolved HCV infection or not (p=0.6). In conclusion, no significant differences were found in the T cell responses of Egyptians to genotype 1b and 4a antigens suggesting that they can benefit from a genotype 1b vaccine.