Hemispherx Biopharma Inc., of Philadelphia, said it entered a formal research agreement to test Alferon N injection, a multispecies, natural alpha interferon, against wild-type and Tamiflu (oseltamivir, Roche AG)-resistant H7N9 influenza virus under the Data Exchange Agreement Annex for Medical Preparedness and Bio-Defense Agreement between the Swiss Surgeon General and the U.S. Department of Defense.