The nonprofit IAVI is financing and coordinating the research, with the goal of starting human testing of SFV-based AIDS vaccines within two years. Bioption and IAVI have agreed to use their joint ownership of any successful AIDS vaccines to provide them to developing countries rapidly and at reasonable prices.

The Bioption-IAVI team expands the roster of European countries partnering with IAVI to accelerate the development and testing of AIDS vaccines. Scientists and biotechnology companies in the UK, Germany and Switzerland are collaborating with IAVI on other AIDS vaccines. The governments of the Netherlands, UK, Ireland, Denmark and Norway provide financial support to IAVI.

"The hunt for a safe and effective AIDS vaccine must be a global effort. Europe in particular has a critical leadership role to play in helping end this terrible epidemic," said Seth F. Berkley, MD, President and CEO of IAVI. "We are confident that we can beat back HIV/AIDS with a preventive vaccine, but not without first committing the world's best talent and resources to the cause."

SFV: Early experiments suggest promise for AIDS vaccination

The Bioption-IAVI AIDS vaccines will be constructed from Semliki Forest Virus (SFV) replicons. An SFV replicon is a genetically engineered version of the naturally occurring alphavirus SFV, modified so it does not cause disease, and further modified to include synthetic copies of a subset of HIV's genetic material. The aim is for SFV replicons to deliver HIV genetic material to human cells, in turn stimulating the immune system to develop defenses against the virus.

There is no risk of the SFV vaccines themselves causing AIDS, as they lack critical components of HIV needed to assemble a functioning virus.

"In laboratory tests, SFV-based AIDS vaccines have shown great promise for safely and effectively inducing anti-HIV immune responses," said Dr. Peter Liljestrom, President and CEO of Bioption and Professor at the Karolinska Institute. "Thus far, experimental SFV vaccines have prevented AIDS in non-human primates. Our next step is to translate these encouraging signs into vaccines for human testing." Bioption is also exploring the use of similar technology for vaccines for other infectious diseases and cancer.

"The Bioption-IAVI team will be looking to see how SFV-based AIDS vaccines stand up against others as far as conferring protection in a way that is practical for developing countries," said Dr. Hans Wigzell, President of the Karolinska Institute. "The ideal is a vaccine that is long-lasting after one or just a few doses. In laboratory testing, SFV-based vaccines have engaged the immune system at lower doses than other candidates."

Like other preventive AIDS vaccines now in development and testing, the Bioption-IAVI vaccines will be intended for individuals uninfected with HIV, to protect them if they are later exposed to the virus.

Accelerating progress through parallel testing of varied vaccine candidates

Over the next few years, Bioption-IAVI SFV vaccines will be tested to evaluate their individual safety and effectiveness -- as well as their promise relative to other vaccines in the IAVI pipeline. IAVI's strategy is to speed the search for a winning vaccine by pursuing a diverse portfolio of possibilities, now numbering more than a half dozen candidates. IAVI hopes to advance the most promising two or three of its vaccines to large-scale, final-stage studies by 2007.

"Each of IAVI's vaccine candidates is a different answer to the question, how do we most effectively package HIV genes into a vaccine to prevent AIDS?" said Dr. Wayne Koff, IAVI's Senior Vice President for Research and Development. "Right now, many technologies for an AIDS vaccine look promising in the laboratory. We must fast-track them toward the ultimate arbiter of success: human trials."

Specifically, the Bioption-IAVI SFV vaccines will be compared against a DNA-based AIDS vaccine (now in human testing with IAVI support by the UK's University of Oxford and Kenya's University of Nairobi) and a bacteria-based candidate (being developed with IAVI sponsorship at the Institute of Human Virology and expected to enter testing early next year by the Uganda Virus Research Institute). Additionally, the SFV, DNA and bacterial vaccines will be tried in combination with a fourth approach, MVA (also now in IAVI-sponsored human testing by Oxford and Nairobi).

A state-of-the-art central laboratory at Imperial College of Science, Technology and Medicine in London will coordinate IAVI's worldwide trials of AIDS vaccines, ensuring that standardized equipment and criteria are used to assess each candidate.

Human trials in partnership with developing countries

Human trials of the Bioption-IAVI SFV-based AIDS vaccines will likely take place in India and potentially other countries in Asia as well as sub-Saharan Africa. All IAVI-sponsored human vaccine trials are conducted by local scientists in the countries hosting the studies, using protocols developed by these researchers and approved by their governments.

Sites in Asia and Africa are slated for trials because the vaccines will be constructed to closely match the strain of HIV, subtype C, common in these regions.

HIV is an extremely variable virus, and it is unclear whether any vaccine designed to work against one subtype of HIV will be effective against the broad spectrum of subtypes circulating worldwide. With most other AIDS vaccine projects focused on HIV subtype B, prevalent mostly in Europe and the US, IAVI and its partners are developing and testing candidates for subtypes common in areas of the developing world where the vast majority of new HIV infections are occurring.

About IAVI

The International AIDS Vaccine Initiative (IAVI; http://www.iavi.org) is a global nonprofit organization working to speed the search for preventive vaccines to protect against HIV and AIDS and assure their global accessibility. IAVI advocates worldwide for increased financial and political commitment to AIDS vaccine science and access. IAVI invests to fast-track promising experimental AIDS vaccines through product development and human testing. Currently, more than a half dozen novel AIDS vaccines are in development with IAVI support, and two are in human testing. IAVI is a Collaborating Centre of the Joint United Nations Programme on HIV/AIDS (UNAIDS), and its major funders include the Bill & Melinda Gates Foundation; the Rockefeller, Sloan and Starr foundations; the World Bank; BD (Becton, Dickinson & Co.); and the governments of the Netherlands, United Kingdom, United States, Canada, Ireland, Denmark and Norway.

About Bioption

Bioption AB is a Swedish biotechnology company focusing on development of vaccines against infectious disease and cancer. The central platform technology is based on recombinant alphavirus molecules that can be delivered both as non-replicating virus particles and as naked DNA.

SOURCE International AIDS Vaccine Initiative Web Site: http://www.iavi.org

www.aegis.org