Hemispherx Biopharma Advances Influenza Vaccine/Immunopotentiation Clinical Trials Designed to Increase Vaccine Dosage Supply and Increase Cross-Protection; Australian Clinical Protocol Complete.

PHILADELPHIA -- Hemispherx Biopharma, Inc. (AMEX: HEB) announced that the Company had completed final design of a well-controlled, Ampligen(R) vs. placebo, immunopotentiation trial of seasonal influenza vaccinations. The design follows closely newly published FDA guidelines for determining potential efficacy. The clinical study seeks to extend the findings from the preclinical models, including primates, being conducted in collaboration with the Japanese National Institute for Infectious Diseases, to determine the extent to which Ampligen(R) may increase the effectiveness of vaccines and thereby broaden the availability of flu vaccine doses to treat more at-risk groups, such as senior citizens.

Ongoing preclinical studies suggest that Ampligen(R), an experimental immunotherapeutic for which an NDA is being prepared for chronic fatigue syndrome (CFS), may achieve two major therapeutic benefits when co-administered with influenza vaccines. First, in studies conducted by the Japanese National Institute of Infectious Diseases (JNIID), protective antibody levels increased up to 100-fold against seasonal influenza viruses. Second, using highly pathogenic lethal avian influenza viruses (HPIV) JNIID found that when co-administered with HPIV vaccines, Ampligen(R) provided cross-protection against variant HPIV strains 100-300 fold.

These are the first scientific reports of potentiation and cross-protection of this magnitude with human or avian influenza viruses.

Variant HPIV has recently been isolated in Indonesia, and may account for the relative ineffectiveness of current vaccines. Specifically, the World Health Organization (WHO) has also noted the increased level of H5N1 in the patients' throat, which is a property associated with more efficient transmission of the virus, and may account for the 100% death rate recently in an Indonesian village.

Indonesian H5N1 deaths averaged one human bird flu death every 2.5 days in May. There are growing concerns for increased bird flu deaths in the wake of the recent earthquake.

Hemispherx Biopharma's clinical programs in flu vaccine use are designed to eliminate and/or mitigate the growing vaccine supply problems and to make the existing vaccines more effective in combating a potential pandemic. Success in this arena will require novel immunological strategies not part of the traditional worldwide vaccine procurement programs.

About Hemispherx

Hemispherx Biopharma, based in Philadelphia, is a biopharmaceutical company engaged in the manufacture and clinical development of new drug entities for treatment of viral and immune-based disorders. Hemispherx Biopharma's flagship products include Alferon(R) and the experimental immunotherapeutics/antivirals Ampligen(R), Alferon LDO and Oragens(TM). Alferon(R) is approved for a category of STD infection, and Ampligen(R) and Oragens(TM) represent experimental nucleic acids being developed for globally important viral diseases and disorders of the immune system. Hemispherx's platform technology includes large and small agent components for potential treatment of various viral infections. Hemispherx has in excess of 100 patents comprising its core intellectual property estate, a fully commercialized product (Alferon(R) N) and GMP certified manufacturing facilities for its novel pharma products. For more information please visit www.hemispherx.net

Information contained in this news release other than historical information, should be considered forward-looking and is subject to various risk factors and uncertainties. For instance, the strategies and operations of Hemispherx involve risk of competition, changing market conditions, change in laws and regulations affecting these industries and numerous other factors discussed in this release and in the Company's filings with the Securities and Exchange Commission. Any specifically referenced investigational drugs and associated technologies of the company (including Ampligen(R), Alferon(R) LDO and Oragens) are experimental in nature and as such are not designated safe and effective by a regulatory authority for general use and are legally available only through clinical trials with the referenced disorders. The forward-looking statements represent the Company's judgment as of the date of this release. The Company disclaims, however, any intent or obligation to update these forward-looking statements. Clinical trials for other potential indications of the approved biologic Alferon(R) do not imply that the product will ever be specifically approved commercially for these other treatment indications.