The first trials of Aids vaccines in Switzerland are set to begin in June.
But even if the tests are successful, experts warn an effective vaccination will not be commercially available for several years.
The launch comes as latest figures show the rate of HIV infection in Switzerland is higher than in neighbouring countries, including France and Germany.
The project, called EuroVacc, will be carried out by the immunology and allergy service at the Lausanne University Hospital, in coordination with a hospital in London, which will begin tests at the same time.
Trials will also begin in the Netherlands, Spain, Italy and Germany at a later date.
The EuroVacc trials will consist of four phases, involving two different prophylactic (preventative) vaccines.
The first vaccine is a DNA-type drug, which contains viral proteins designed to encourage the human body to kill the infected cells
The second vaccine is a "viral carrier". It works in the same way as the first vaccine, but instead of proteins, it carries a recombinant (synthetic) virus, called NYVAC.
Jean-Pierre Kraehenbuhl, vice-president of the EuroVacc project and a researcher at the Institute of Biochemistry at the University of Lausanne, insists that the vaccines are safe.
"The vaccines pose no risk of infection for the volunteers," he told swissinfo. "We will not be injecting the Aids virus or even a diluted form of the HIV virus, as is done for the smallpox vaccine."
"Nor does the synthetic virus in the second vaccine pose any risk of infection."
The first two phases will test the body's tolerance to the vaccines and whether the vaccines' presence induces the immune system to respond.
In the first phase, the vaccines will be tested on 80 volunteers who are in good health and who are not from social groups that are most at risk of contracting HIV.
Secondly, people from groups considered to be at a high risk of catching HIV will be tested. These groups include homosexuals, drug users and sex workers.
By 2006 to 2007, EuroVacc plans to begin the final two phases of the trials.
At this point, the vaccines will be tested on the Aids virus itself, using volunteers who are already infected. Researchers hope to test around 100 people.
A significant part of the final trials will be conducted on infected people in countries where Aids poses a significant health problem, for example Asia, Africa and eastern Europe.
"For the fourth phase, we have already made deals with Tanzania, Rwanda, South Africa, China and Russia," Kraehenbuhl said.
He added that it was important to conduct trials in high-risk countries since the vaccine neeeded to be tested as widely as possible to ensure its effectiveness.
Meanwhile, the United States is also conducting its own vaccine trials, similar to the EuroVacc project. The US project is called HVTN (HIV Vaccine Trial Network).
In order to ensure that effective vaccines developed by projects such as EuroVacc can be used in the US and vice versa, the US is due to sign a collaboration deal with Europe in May. It will be the first accord of its kind.
By signing the deal, European and United States teams hope to facilitate the search for an effective cure for Aids.
EuroVacc was formed five years ago. To date, more than 30 research teams in eight European countries have been involved in the project.
On completion, the project is estimated to have cost between €20 and 30 million. It is financed by the European Union, the US, and the EuroVacc foundation, in collaboration with several businesses.
swissinfo, Jean-Louis Thomas (translation: Joanne Shields)
Aids vaccine tests will begin in Switzerland in June 2003.
Some 80 volunteers will be tested under the project, called EuroVacc.
The trials will last four years.
The trials involve two separate vaccines.
A hospital in London will conduct trials at the same time, as part of the same project.