(Stockholm) One of the scientists sharing the Nobel Prize in medicine for discovering the HIV virus said on the weekend that he believes there will be a therapeutic vaccine to treat it within five years.

He did not elaborate as to why he believes scientists are close.

Scientists have developed lifesaving drugs that can inhibit the disease but there is no vaccine to prevent or treat HIV infection. Finding a vaccine has proved elusive in the past, with the most recent trials ending in failure.

However, a therapeutic vaccine would be a key step in fighting the virus, he said. A therapeutic vaccine would be given to people who are already infected, in order to lessen the impact of the disease while a preventative vaccine would, ideally, protect people from HIV.

So far, scientists have focused on drugs to fight the disease because they have been proving effective. In developed countries, AIDS has become manageable, rather than fatal, because of the drugs.

HIV was first identified 25 years ago but still poses difficult challenges. Scientists cannot explain, for example, why it causes the immune system to collapse.

Montagnier, together with other Nobel laureates, began arriving in Stockholm on Saturday ahead of a week of Nobel festivities that culminates with a lavish banquet and awards ceremony Dec. 10.

The 76-year old scientist shares one-half of the US$1.2-million prize with 61-year-old Francoise Barre-Sinoussi, also of France, for their research on HIV. The other half goes to Germany’s Harald zur Hausen, 72, for showing a viral cause for cervical cancer.

Sweden’s King Carl Gustaf will hand over the Nobel Prize in Physiology or Medicine on Wednesday, along with the awards in chemistry, physics, literature and economics. The Nobel Peace Prize is presented at a separate ceremony in Oslo, Norway.