Vaccine for HIV-Hepatitis C Coinfection May Become Reality

A combination of investigational HIV and hepatitis C virus (HCV) vaccinations could become a reality in the future for patients coinfected with the diseases, a recent study suggests.

Analysis presented at The International Liver Congress 2016 showed a “prime boost” approach is compatible with co-administration of vectors encoding HIV and HCV antigens.

“While we have drugs to treat both HIV and HCV, these are out of reach for many and do not prevent reinfection,” said principal study investigator Lucy Dorrell.

During the study, the immune system was first primed by exposure to non-replicative serologically distinct adenoviral vectors containing fragments of HIV and HCV viruses.

The HCV and HIV booster vaccinations were then inserted into a vaccination virus strain commonly used in clinical trials — an MVA vector.

“Knowing that it may be possible to vaccinate a single individual against both diseases opens up huge possibilities for rolling back epidemics of disease and co-infection,” said researcher Ellie Barnes.

During a phase 1 clinical trial, 32 healthy volunteers were divided amongst 3 groups: group 1 received HCV investigational vaccines at weeks 0 and 8; group 2 received HIV investigational vaccines at weeks 0 and 8; and group 3 were co-administered both HCV and HIV investigational vaccines.

The vaccine priming against HIV and HCV induced an immune response within the body. This response was measured by the number of HIV and HCV specific T cells found in a sample of blood, with a peak mean of 608.5 and 785 spot forming units per million peripheral blood mononuclear cells SFU/106PBMC, respectively.

After the boost vaccination, the immune responses were increased (peak mean 4260 SFU/106PBMC for HCV and 3760 SFU/106PBMC for HIV).

Vaccines were administered to participants as an intramuscular injection and were well tolerated.

Additionally, the co-administration of the HCV and HIV components of the boost did not impair the magnitude of either HCV-specific or HIV-specific T cell responses compared with individual administration.

“Finding effective vaccinations against the world's biggest killers is a huge and pressing problem,” said researcher Laurent Castera. “This study shows for the first time that it is possible to generate simultaneous immune response against diseases HCV and HIV, raising the possibility of a combined vaccination.”