Timothy Webb and other advocates protest the cost of HIV drugs manufactured by the pharmaceutical company Gilead outside an AIDS conference in Atlanta in March. Gilead is making a new hepatitis C drug, Sovaldi. John Amis/AP Images for AIDS Healthcare Foundation hide caption

itoggle caption John Amis/AP Images for AIDS Healthcare Foundation

A colorized closeup of the hepatitis C virus. James Cavallini/Science Source hide caption

itoggle caption James Cavallini/Science Source

Particles of the hepatitis C virus are imaged with an electron microscope. James Cavallini/Science Source hide caption

itoggle caption James Cavallini/Science Source

Hepatitis C patient Nancy Turner shows Kathleen Coleman, a nurse practitioner, where a forearm rash, a side effect of her treatment, has healed. Turner is one of many patients with hepatitis C experimenting with new drugs to beat back the virus. Richard Knox/NPR hide caption

itoggle caption Richard Knox/NPR

Hospitals began testing blood for hepatitis in 1992, so anyone who received a blood transfusion before then is at an increased risk for contracting the disease. iStockphoto hide caption

itoggle caption iStockphoto

Gregg Allman and Natalie Cole perform at the Tune In to Hep C benefit concert at the Beacon Theatre in New York on July 27, 2011. Both singers have battled chronic hepatitis C. Rob Bennett/AP Images for TuneInToHepC.com hide caption

itoggle caption Rob Bennett/AP Images for TuneInToHepC.com

This photo provided by the U.S. Attorney's Office in New Hampshire shows David Kwiatkowski, a former lab technician at an Exeter, N.H., hospital. AP Photo/U.S. Attorney's Office hide caption

itoggle caption AP Photo/U.S. Attorney's Office

Dr. Paul J. Pockros, a liver specialist at Scripps Green Hospital in San Diego, talks with hepatitis C patient Loretta Roberts in Jan. 2011. Lenny Ignelzi/AP hide caption

itoggle caption Lenny Ignelzi/AP