EASL 2016: Vaccines for HIV and Hepatitis C Could Potentially Be Administered Together

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Immunization against HIV and hepatitis C virus (HCV) could potentially be combined without compromising immune response to either, though effective vaccines for both diseases are still elusive, according to research presented at the European Association for the Study of the Liver's International Liver Congress (EASL 2016) last week in Barcelona.

Effective vaccines to prevent HIV and hepatitis C are major public health goals, aiming to prevent infections that lead to the death of millions of people worldwide each year. Development and wide-scale deployment of a hepatitis B virus (HBV) vaccine -- which is now part of the routine childhood vaccination series in many countries -- has led to a sharp decline in new infections, showing what can be achieved.

Unfortunately, HIV and HCV vaccines have proven difficult to develop, in part due to the high genetic variability of both viruses. But research presented at the conference suggests that vaccine components that target these viruses can potentially be administered together without compromising their effectiveness, which could optimize use of public health resources for prevention programs.

Below is an edited excerpt from an EASL press release summarizing the study findings.

Combined HIV and Hepatitis C Virus Vaccination a Possibility

Study finds no impairment of immune response when vaccinations against hepatitis C and HIV are administered together

April 13, 2016 -- Barcelona, Spain -- A combined vaccination against hepatitis C virus (HCV) and HIV moved a step closer, with the results of a study presented at The International Liver Congress 2016 in Barcelona, Spain today.

An estimated 2.3 million people globally are coinfected with HIV and HCV. HCV is the leading cause of non-AIDS deaths in coinfected individuals.

The research showed that the "prime-boost" approach is compatible with co-administration of vectors encoding for HIV and HCV antigens (molecules capable of inducing an immune response). In this approach, the immune system is first primed through exposure to non-replicative serologically distinct adenoviral vectors that contain fragments of HCV and HIV viruses. Following this, booster vaccinations are given with the same combination of HCV and HIV fragments, each inserted into an MVA vector, a vaccination virus strain commonly used in clinical trials.

"While we have drugs to treat both HIV and HCV, these are out of reach for many and do not prevent reinfection," said Professor Lucy Dorrell of the University of Oxford, who is the principal investigator of the study. Her study fellow, Professor Ellie Barnes, who is leading the development of HCV vaccines at the University of Oxford, continues, "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 coinfection."

The Phase 1 study enrolled 32 healthy volunteers in three groups. Group one received only HCV investigational vaccines at weeks 0 and 8. The second group received only HIV investigational vaccines following the same dosing schedule. The final group received both HCV and HIV investigational vaccines that were co-administered.

Vaccine priming against HCV and HIV induced immune response in the body, measured by the number of HIV and HCV specific T-cells found in a sample of blood (peak mean of 608.5 and 785 spot-forming units per million peripheral blood mononuclear cells [SFU/106PBMC] respectively). These immune responses were increased following boost vaccination (peak mean 4260 SFU/106PBMC for HCV and 3760 SFU/106PBMC for HIV).

Co-administration of HCV and HIV components of the boost did not impair the magnitude or breadth of either HCV or HIV specific T-cell responses compared to each alone. All vaccines were given as an intramuscular injection and both were well tolerated.

"Finding effective vaccinations against the world's biggest killers is a huge and pressing problem," said Professor Laurent Castera, EASL Secretary General. "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."

About The International Liver Congress

This annual congress is the biggest event in the EASL calendar, attracting scientific and medical experts from around the world to learn about the latest in liver research. Attending specialists present, share, debate and conclude on the latest science and research in hepatology, working to enhance the treatment and management of liver disease in clinical practice. This year, the congress is expected to attract approximately 10,000 delegates from all corners of the globe. The International Liver Congress takes place from April 13-17, 2016, at the Fira Barcelona Gran Via, Barcelona, Spain.

About EASL

Since EASL's foundation in 1966, this not-for-profit organization has grown to over 4,000 members from all over the world, including many of the leading hepatologists in Europe and beyond. EASL is the leading liver association in Europe, having evolved into a major European Association with international influence, with an impressive track record in promoting research in liver disease, supporting wider education and promoting changes in European liver policy.

4/22/16

Reference

F Hartnell, A Brown, E Ghaffari, et al. Co-Administration of Chimpanzee Adenoviral Vectors of Different Serotypes, for the Prevention of HCV and HIV Co-Infection. EASL International Liver Congress 2016. Barcelona, April 13-17, 2016. Abstract LPB07.

Other Source

EASL. Combined HIV and hepatitis C virus vaccination a possibility. Press release. April 13, 2016.