Hemispherx Biopharma's Ampligen(R) Cited at Barcelona Vaccine & Active Immunotherapeutics Forum 2011 PHILADELPHIA, May 12, 2011 (GLOBE NEWSWIRE) -- Hemispherx Biopharma, Inc. (NYSE Amex:HEB) (the "Company" or "Hemispherx") today announced that Ampligen® will be featured in a discussion of...