Stage: Phase II pending.
Why It MattersHepatitis C virus is the most common chronic blood-borne infection in the world, having infected an estimated 170 million people. It is the leading cause of liver transplants in the West, and complications from it killed famed Beat poet Allen Ginsberg. The viral disease currently causes 10,000 deaths annually in the United States alone, and its annual toll is expected to triple in the next 10 to 20 years.
How It WorksA number of therapeutic vaccines are in development that help treat patients already infected with the disease, but the Novartis effort may be the first prophylactic (preventative) vaccine against hepatitis C to enter phase II. A team headed by Michael Houghton, who helped discover the hepatitis C virus, is developing the vaccine for Novartis. It combines sugary proteins derived from the surface of the virus with an oil-in-water emulsion meant to enhance the body's immune responses. In its phase I trial, all 45 healthy volunteers given the vaccine successfully generated neutralizing antibodies against hepatitis C.
"It's probably the furthest along in development of the prophylactic vaccines, but a lot of us don't think such a vaccine will work so well," says Jake Liang at the National Institute of Diabetes and Digestive and Kidney Diseases. The problem is that Hepatitis C can rapidly mutate to fool antibodies matched to the virus.
Instead of working through antibody-mediated immunity, Liang says successful prophylactic vaccines against the virus might have to work through cell-mediated immunity, which means immune cells are taught to attack infected cells. Such prophylactic vaccines against hepatitis C are still in preclinical phases, however.