AIDS: Vaccine shows positive results in small trial - researchers

October 19, 2009

An HIV vaccine tested in Tanzania has shown positive results in preliminary trials and may provide better protection than a promising Thai vaccine unveiled on September 24, Swedish researchers said Monday.

"We hope that our vaccine could increase protection to 50 percent," Britta Wahren, a professor emeritus at Sweden's Karolinska Institute and one of the researchers involved in the study, told AFP.

The vaccine in Thailand tested by Thai and US researchers cuts the risk of HIV infection by a third, an achievement described by the World Health Organisation (WHO) as a "significant scientific advance."

"Our vaccine includes more strains of the virus -- from Europe, Africa, the US and Asia -- and therefore provides a broader protection," Wahren said.

The Swedish vaccine, called Hivis, was tested on 60 healthy policemen in Tanzania in what is called a Phase II study.

This is the stage between a Phase I trial, when a vaccine is tested on a very small group of volunteers to assess its safety, and a Phase III trial, a large-scale investigation among thousands of people that focusses especially on effectiveness.

The researchers looked at whether the vaccine was safe to use and how the body's immune system reacted to it.

The results were so encouraging that the researchers are keen to carry Phase III testing, Wahren said.

"We don't have the financing to do that yet. But we hope that we will get it after presenting our results," Wahren said.

The results have not yet been published in a scientific journal but are to be presented at an HIV/AIDS vaccine conference in Paris on Wednesday.

Manuel Romaris, the scientific officer in charge of research on HIV/AIDS at the European Commission, said the Swedish vaccine had shown the most promising preliminary results so far.

"It is the best preliminary result I know of for a vaccine of this type ... The Swedish researchers seem to be on the right path," Romaris told leading Swedish paper Dagens Nyheter.

"I don't think the Thai vaccine's results were as good in the early stages," he added.

The Thai vaccine was tested on 16,000 healthy Thai people in a Phase III study.

(c) 2009 AFP