Exhibit 99.1

     VaxGen Reports Positive Results of Animal Efficacy Studies of Smallpox
                                Vaccine Candidate

      BRISBANE, Calif. - April 14, 2004 - VaxGen, Inc. (Nasdaq: VXGN) today
announced top-line results from two animal studies of the effectiveness of its
attenuated smallpox vaccine candidate, LC16m8. Both studies, which were
conducted in mice and rabbits, respectively, demonstrated that a single dose of
LC16m8 was as effective as the currently licensed vaccine, DryVax, in protecting
against a lethal poxvirus challenge. LC16m8 is a live attenuated vaccinia
vaccine and has been licensed for use in humans in Japan since 1980.

      "These are the first animal efficacy studies to be reported which directly
compare the effectiveness of LC16m8 and Dryvax," said Lance K. Gordon, Ph.D.,
VaxGen's president and chief executive officer. "Results of these new studies
demonstrate that the vaccine is as effective as DryVax in controlled challenge
studies in two animal species."

      Dr. Gordon will discuss these findings at the Biodefense Vaccines,
Therapeutics and Diagnostics conference today in Washington, D.C. Results from
these studies will be presented in further detail at the 7th Annual Conference
on Vaccine Research of the National Foundation for Infectious Diseases
(www.nfid.org/conferences/vaccine04), which is scheduled to take place from May
24-26 in Arlington, Virginia. The studies were funded by VaxGen and the National
Institute of Allergy and Infectious Diseases, part of the U.S. National
Institutes of Health. VaxGen is developing LC16m8 in collaboration with the
Chemo-Sero-Therapeutic Institute (Kaketsuken) of Japan. The company plans to
begin a Phase I/II trial in humans to study LC16m8's safety and immunogenicity,
the ability of the vaccine to induce an immune response, later this year. VaxGen
also intends to initiate a large-scale safety trial in the second half of 2004.
Additional animal studies are also planned.

      About LC16m8

      In collaboration with the Chemo-Sero Therapeutic Research Institute
(Kaketsuken) of Japan, VaxGen is developing LC16m8 for use in the United States
and potentially elsewhere. LC16m8 is a next-generation, attenuated smallpox
vaccine that is designed to have a better safety profile, yet be equally
effective, compared to conventional smallpox vaccines. LC16m8 has been licensed
for use in Japan since 1980 and forms the basis for that country's smallpox
vaccine stockpile. It is the only attenuated vaccine to be licensed for use in
humans to prevent smallpox infection.

      LC16m8 has been used in laboratory workers, medical and emergency response
personnel and has been administered to 50,000 children in Japan. LC16m8 is
produced in cell culture from vaccinia virus that has been attenuated, or
modified, so that it can initiate an immune response without causing serious
adverse side effects.



      About VaxGen

      VaxGen, Inc. is a biopharmaceutical company engaged in the development,
manufacture and commercialization of biologic products for the prevention and
treatment of human infectious diseases. Based in Brisbane, Calif., the company
is developing preventive vaccines against anthrax, smallpox and plague and an
anthrax monoclonal antibody in collaboration with AVANIR Pharmaceuticals. The
company is also the largest shareholder in Celltrion, Inc., a joint venture
formed to build operations for the manufacture of biopharmaceutical products,
including VaxGen's product candidates. For more information, please visit the
company's web site at: www.vaxgen.com.

NOTE: This press release contains "forward-looking statements" within the
meaning of the federal securities laws. These forward-looking statements include
without limitation, statements regarding the timing, progress and results of
VaxGen's clinical development of LC16m8, the ultimate safety and efficacy of
LC16m8 and VaxGen's ability or intentions to sell the vaccine. These statements
are subject to risks and uncertainties that could cause actual results and
events to differ materially from those anticipated. Reference should be made to
Item 1 of the company's Annual Report on Form 10-K filed by VaxGen in March 30,
2004 under the heading "Additional Business Risks" for a more detailed
description of such factors. Readers are cautioned not to place undue reliance
on these forward-looking statements that speak only as of the date of this
release. VaxGen undertakes no obligation to update publicly any forward-looking
statements to reflect new information, events, or circumstances after the date
of this release except as required by law.

Media Contact

Kesinee Angkustsiri Yip
Associate Director, Corporate Communications
Mobile: 650-238-4685 (at the Biodefense Vaccines conference 4/14/04)
Office: 650-624-2304

Investor Contact

Lance Ignon
Vice President, Corporate Affairs
650-624-1041