TAMPA, FLORIDA - May 2009 - The following letter is from Samuel S. Duffey, President and General Counsel of Accentia Biopharmaceuticals, Inc. (Other OTC: ABPIQ) and its majority-owned subsidiary, Biovest International, Inc. (Other OTC: BVTI).

Dear Valued Partners, Clients, Shareholders, Employees, and Friends:

For many months now, we have been witnessing an economy unlike any other in our lifetimes with consequences that have been devastating for so many, and may get worse for many more. Despite the obvious challenges this market environment presents, Accentia and Biovest continue to navigate these difficult times with confidence and measured success, as we strive to bring novel therapies to market for many serious and life-threatening diseases, and offer biomanufacturing solutions, along with expert bio/pharma consulting services. I believe the ongoing reorganization proceeding, which we began in November 2008, has been a positive step to cost-effectively streamline our operations, while maintaining, and in some cases even improving our productivity. And I am convinced that corporately we are taking the right steps to solidify and grow our existing businesses, while preserving and enhancing our ongoing drug development opportunities. I would like to take this opportunity to provide a brief update on our businesses and programs.

BiovaxID®

Through our majority-owned subsidiary, Biovest International, we are committed to bringing BiovaxID, our novel, personalized anti-cancer vaccine for indolent follicular non-Hodgkin's lymphoma, to market, and ultimately to expand its indications to include the treatment of other kinds of B-cell blood cancers. This is truly an individualized patient-specific therapy, as cancerous cells, collected by biopsy from each patient, are engineered into a therapeutic vaccine, training the immune system to recognize cancerous cells as foreign (by using unique antigens only expressed on the tumors), thus mounting a highly targeted, potent and durable response, while sparing healthy cells.

We believe that our pivotal Phase III clinical trial demonstrated a meaningful therapeutic benefit, and we are preparing to present the trial data for discussions with the U.S. FDA, the European Union's EMEA, and other select international regulatory agencies. These meetings will determine the next steps in seeking potential global approvals.

While the top-line results have been announced, the more complete end-of-study results and biostatistical analysis are expected to be reported at the American Society of Clinical Oncology Annual Meeting (ASCO) to be held May 29th - June 2nd in Orlando, Florida. In addition, we anticipate the publication of these results in a leading peer-reviewed journal later this year.

Concurrent with our strategies to seek international regulatory approvals, we are preparing to make BiovaxID available to patients in Europe for the treatment of non-Hodgkin's lymphoma under a Named-Patient Program, which allows physicians and patients to purchase the vaccine on a compassionate-use basis, provided the appropriate protocols are followed. Under the European Named-Patient Program, BiovaxID may also be obtained for the treatment of other B-cell blood cancers as well, such as mantle cell lymphoma, chronic lymphocytic leukemia and multiple myeloma.

We are working closely with our partners at IDIS Limited, a leading UK-based drug distributor, to soon start this compassionate-use program throughout Europe. Biopsies for the first group of patients will likely begin very soon, so that we can collect the patient-specific cells necessary for us to manufacture each personalized vaccine.

In addition to the ASCO Annual Meeting, we expect to make presentations at leading upcoming cancer and lymphoma conferences, and I expect we will make such announcements in the near future.

Our manufacturing expertise in the production of personalized vaccines and monoclonal antibodies can be directly attributed to our proprietary Advanced Hollow Fiber technology. Based on such, we market a diverse line of bioreactors, including the AutovaxID™, offering many advantages over other bio-production systems. This leads me to discuss another one of Biovest's core business segments, our cell culture division, which is primed for significant growth.

Cell Culture and Biomanufacturing Instruments Division

For more than 20 years, Biovest's cell culture services division has been providing expert customized cell culture services and contract manufacturing services for clients ranging from University researchers to blue-chip pharmaceutical and biopharmaceutical customers. We are indeed proud that our cell culture team is recognized as a key resource in providing cost-effective and efficient biomanufacturing solutions, offering flexible scalability options. Notwithstanding the economic challenges, we have recently made additional resource investments in this important business.

Our team markets a line of proprietary Advanced Hollow Fiber bioreactors, which are ideally suited for the production of monoclonal antibodies (therapeutic and diagnostic), other recombinant proteins and personalized vaccines. Of these bioreactors, it is the AutovaxID system that produces BiovaxID so efficiently. Our engineering team, with their expertise in hollow-fiber cell instruments, expects to further develop the AutovaxID system to grow new types of cells, such as those used in vaccine production and patient-specific cells for revolutionary treatments to rebuild damaged tissue or organs and repair severe burns. As previously announced, the U.S. Federal Government has approved the appropriation of $1.6 million in biomedical research funds for Fiscal Year 2009 for the Defense Department's Cancer Immunotherapy and Cell Therapy Initiative. This anticipated contract and related funding is earmarked for expanding the automated capabilities of AutovaxID, and we fully expect to report key milestones on this work throughout the year.

With such valuable prospects, we are absolutely committed to growing our cell culture business, and we are currently investing in upgrades to our 33,000 sq. ft. Minneapolis facility, including our planned new cancer vaccine manufacturing capacity. I want to assure our valued clients that we will not only continue, but expand our superior biomanufacturing solutions, accompanied by the outstanding support and service which have become the foundations of our reputation.

Analytica International, Inc.

A wholly-owned subsidiary of Accentia, Analytica is a broadly recognized and highly regarded international consulting company. With successful operations in both New York and Germany, we provide a broad range of health economic consulting services to some of the largest and leading pharmaceutical and biotechnology companies in the world. We are proud of this expert group of research professionals, many at the Master's and Doctoral levels, and we are dedicated to expanding this business. These invaluable services are provided to both emerging biotechs and "big-pharma", and we will continue to build on Analytica's reputation as a leading source of innovative and comprehensive intelligence on the economics of disease states, drug therapies, medical devices, and biotechnologies.

Revimmune

We continue to remain very excited about the future for Revimmune therapy (a system of care using ultra-high-dose cyclophosphamide) particularly as potential new revolutionary treatment for multiple sclerosis (MS) and for its use in preventing the rejection of bone marrow transplants, such as in cases seeking to cure sickle-cell anemia. While additional clinical studies are necessary in order to seek approvals, the preliminary study results reported by our partners at Johns Hopkins University have been remarkable, with unprecedented results reported in the treatment of multiple sclerosis. We are currently exploring various strategic opportunities to sponsor and/or fund advancement of the Revimmune program in order to file an Investigational New Drug (IND) application and proceed with a clinical trial with the goal of demonstrating improvements in patient's neurological and physical functions - a striking departure from standard MS trials which measure success by only delaying the inevitable progression of disease.

SinuNase

We remain committed to advancing novel products to market for the treatment of chronic sinusitis, a debilitating sinus condition that affects approximately 60 million patients in the U.S. and Europe. In doing so, we are working on various development and regulatory plans for SinuNase and potentially other related products. While it is likely we will need to complete new clinical trials in order to seek regulatory approvals for SinuNase, I am hopeful that we will soon be able to unveil a novel approach to bring the first effective treatment for chronic sinusitis to market. As with Revimmune, we are exploring strategic funding opportunities to support this program's advancement.

In Closing

Our plans are ambitious, but, in my opinion, realistic. We are positioned to react to the new economy, and we have committed our best efforts to grow our business. And, despite the many risks, I have a high degree of confidence that our passionate and talented team of professionals will realize many successes, yielding vastly improved results, as we strive to build the kind of Company we can all be very proud of.

Sincerely yours,

Samuel S. Duffey

Samuel S. Duffey, Esq.
President and General Counsel
Accentia Biopharmaceuticals, Inc.
Biovest International, Inc.

About Accentia Biopharmaceuticals, Inc.

Accentia Biopharmaceuticals, Inc. (Other OTC: ABPIQ) and its subsidiaries, including majority-owned Biovest International, Inc. (OTCBB: BVTIQ), are committed to achieving significant long-term growth through: the research, development and commercialization of novel therapeutic drugs for the treatment of chronic and life-threatening immune diseases; delivering expert contract cell culture manufacturing services; marketing an innovative line of efficient, cost-effective Advanced Hollow Fiber biomanufacturing systems; and providing a broad range of pharmaceutical consulting services. Accentia is a portfolio company of the Hopkins Capital Group.

Accentia Biopharmaceuticals, Inc. Corporate Contact:
Douglas Calder, Director of Investor Relations & Public Relations,
Phone: (813) 864-2554, ext.258 / Email: dwcalder@accentia.net

Forward-Looking Statements:

Statements in this release that are not strictly historical in nature constitute "forward-looking statements." Such statements include, but are not limited to, statements about BiovaxID®, Revimmune™SinuNase™, AutovaxID™ and any other statements relating to products, product candidates, product development programs, the FDA or clinical study process including the commencement, process, or completion of clinical trials or the regulatory process. Such statements may include, without limitation, statements with respect to the Company's plans, objectives, expectations and intentions, and other statements identified by words such as "may," "could," "would," "should," "believes," "expects," "anticipates," "estimates," "intends," "plans," or similar expressions. Such forward-looking statements involve known and unknown risks, uncertainties, and other factors that may cause the actual results of Accentia to be materially different from historical results or from any results expressed or implied by such forward-looking statements. These factors include, but are not limited to, risks and uncertainties related to the progress, timing, cost, and results of clinical trials and product development programs; difficulties or delays in obtaining regulatory approval for product candidates; competition from other pharmaceutical or biotechnology companies; and the additional risks discussed in filings with the Securities and Exchange Commission. All forward-looking statements are qualified in their entirety by this cautionary statement, and Accentia undertakes no obligation to revise or update this news release to reflect events or circumstances after the date hereof. The product names used in this statement are for identification purposes only. All trademarks and registered trademarks are the property of their respective owners.