Developments in HIV Vaccine, Hepatitis C Care Expand Options for Co-Infected Patients, But Access Remains Limited

Researchers discussed new HIV vaccine developments in protecting antibodies capable of neutralizing many different strains of the virus and reviewed the comorbidity of HIV and hepatitis C virus (HCV).

During a plenary session at the 7th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention (IAS 2013) held June 30 to July 3 in Kuala Lumpur, Malaysia, researchers discussed new HIV vaccine developments in protecting antibodies capable of neutralizing many different strains of the virus and reviewed the comorbidity of HIV and hepatitis C virus (HCV).

Dennis Burton, PhD, a professor of immunology and microbiology at the nonprofit Scripps Research Institute in California, said in a press release that many researchers presently believe that “in order to be successful, an HIV vaccine will need to induce broadly neutralizing antibodies capable of neutralizing many different strains of virus.” However, Burton noted that classical vaccination strategies for inducing those antibodies — including live attenuated virus and killed virus — haven’t been successful. Explaining that the antibodies’ binding to the HIV envelope spike at the virus’s molecular surface is what makes it non-infectious, Burton said an alternative approach is based on that understanding of “how broadly neutralizing antibodies interact with this spike.”

“With examination of more and more of the broadly neutralizing antibodies, some of the hurdles to inducing them through vaccination become clearer,” Burton said in a press release. “At this moment, many insights are being obtained and many vaccine candidates are being designed and tested. It is hoped that this rational design approach will begin to give signs of success within the near future.”

But Karine Lacombe, MD, PhD, an associate professor of infectious and tropical diseases at Saint-Antoine Hospital in Paris, France, noted that those HIV vaccine developments don’t address HCV chronically carried in roughly 25 percent of HIV-infection patients, which can lead to liver-related morbidity and mortality “because of the intricate and deleterious influence both viruses have upon one another,” she said in a press release.

However, as a result of recent shifts in HCV care from long treatment courses of “ribavirin-based bitherapy with major side effects and low response rate, to well-tolerated and short courses based on two, three, or four-drug regimens,” Lacombe said HCV cure is becoming a reality in those co-infected patients. Still, Lacombe said the cost and human resources constraints continue to restrict access to those innovative HCV therapies for the majority of the co-infected world.

“HIV comorbidity is one of the most pressing issues that we need to address in HIV,” IAS 2013 International Chair and International AIDS Society President Françoise Barré-Sinoussi added in a press release. “There is no doubt that new studies on tuberculosis and hepatitis C will contribute to better integrate research and improve multidisciplinary coordination. In the case of HCV, injecting drug use is the main driver of infection, and we face similar challenges in terms of stigma and discrimination towards infected people.”