The first and only preventative HIV vaccine showed no adverse effects in a human preliminary trial, Canadian scientists said on Tuesday.

Dr Chil-Yong Kang and his team at Western University said the SAV001-H vaccine holds "tremendous promise" for success in the final phases of testing now that the first hurdle has been accomplished.

Sumagen Canada, a company that supported the clinical development of the vaccine, said that patient enrollment has progressed smoothly and there have been no adverse effects observed including local reactions, signs/symptoms and laboratory toxicities after patients were injected with the genetically modified killed-whole virus.

Men and women aged 18 to 50 were enrolled in the study and randomised to be treated with the vaccine or a placebo.

The interim data showed a significant increase in the HIV-1 antibody formations after SAV001-H administration compared to the base line in some patients, Sumagen said in a statement.

Sumagen spokesperson Dr Dong Joon Kim said; "We have proven that there is no safety concern of SAV001-H in human administration and we are now prepared to take the next steps towards Phase II and Phase III clinical trials. We are delighted to be one step closer to the first commercialised HIV vaccine."

A Phase II trial will later measure immune responses in humans, involving approximately 600 HIV-negative volunteers who are in the high-risk category for HIV infection.

Finally, a Phase III study will measure the efficacy of the vaccine, involving approximately 6,000 HIV-negative volunteers who are also in the high-risk category for HIV infection.

Image: Interim data showed an increase in HIV-1 antibody formations in those patients injected with SAV001-H. Photo: Courtesy of