Australian HIV vaccine trial touted for 2003

A public consortium of researchers is hoping to get permission to start a Phase I clinical trial of a new HIV vaccine early in the new year.

"Right now protocols are subject to review by the regulatory agencies," said Dr Sean Emery, head of the therapeutic research program at the National Centre in HIV Epidemiology and Clinical Research, based at the University of NSW.

The vaccine is the result of the combined efforts of researchers at a number of institutes including the University of Melbourne, the John Curtin School of Medical Research at the Australian National University (ANU), and the University of Newcastle, as well as CSIRO, and the Australian Federation of AIDS Organisations. The project is funded by the US National Institutes of Health (NIH), through a $27 million grant.

Based on the 'prime and boost' technology first developed at CSIRO and ANU, the vaccine has a two-pronged approach, first delivering viral genes as naked DNA (the 'prime') and then via a fowlpox viral vector (the 'boost'). The DNA prime is taken up by cells which then express and present the viral proteins to the immune system, thus priming it. The fowlpox vector then boosts the immune response even more.

The technology has been thoroughly evaluated in pre-clinical studies, including mouse studies performed by Ian Ramshaw at ANU and studies in macaque monkeys performed by Stephen Kent at the University of Melbourne. The vaccination regimen has been shown in animal studies to substantially improve cell-mediated immunity, which is critical to developing a protective immune response.

The Phase I trial will involve 24 HIV-negative volunteers at St Vincent's Hospital in Sydney and is expected to last a year. The volunteers will receive three doses of vaccine material -- two DNA primes and one fowlpox boost -- over a period of eight weeks.

"The purpose of the first study is to demonstrate the safety of the vaccine and to get a handle on cell mediated immunity in humans following administration," explained Emery.

He said that the consortium hoped to get permission from the Therapeutic Goods Administration (TGA) to begin the trials in January.