South African AIDS Vaccine Initiative (SAAVI) scientists and co-workers will present some 25 papers at the World AIDS Conference to be held in Durban in July.

Dr Walter Prozesky, research co-ordinator at the Medical Research Council and head of SAAVI, will chair a round table session on the vaccine for Africa at the conference.

Prozesky said SA scientists have agreed to set a goal to develop a model or proto-type vaccine by 2005.

He said the vaccine had to be affordable and generally accessible to all countries that form part of the Southern African Development Community.

“It is an educated guess in the end, but in my opinion we will have a vaccine within the next five years,” Prozesky said.

Phase 1 of the trials will involve about 45 volunteers from various backgrounds and states of health.

This phase will assess the safety and possible serious side effects of the drug, necessitating such a small group.

Phase 2 will involve between 200 and 300 volunteers. “It will be a spectrum of people who will be tested to answer various questions such as more data on safety issues as well as an indication of proof on principle.

In other words does the vaccine really do something to their immune system,” Prozesky said.

This could include women, men, people who already have AIDS and children.

Phase 3 will involve between 2 000 and 3 000 volunteers in a real life situation.

“Here we will go into an area with high infection rates. Half of the people will be immunised with a placebo vaccine and the other half with the real vaccine,” Prozesky explained.

The trial will be double blind, which means nobody, except for the computer will know who received which vaccine.

At the end the code is broken with results on whether the vaccine worked.

“This part of the trial does pose many ethical problems and you may have falsely raised the hopes of those who received the placebo vaccine,” he said.

Prozesky confirmed that they recently met with the MCC to establish what “they would want us to put before them (in our application for phase 1)”.

“The delay in our vaccine development is caused mainly by waiting for the results of the different phases before going on to the next one,” he added.

Prozesky said they had two vaccines “that we would apply for phase 1 trials” which would probably commence early next year.

He said one testing site would definitely be in Durban or Hlabisa in KwaZulu-Natal, while the other would be either Chris Hani Baragwanath Hospital in Soweto on the University of Stellenbosch Medical School at Tygerberg Hospital in Cape Town.

He said four candidate vaccines were being developed at the University of Cape Town and one at the University of Stellenbosch.

“These vaccines could take a while because the development started later than those overseas.”

He said in the fast track group, which involved collaboration between South African and American scientists, two vaccines should be up for testing by early next year.

Prozesky said there were about 30 vaccines already being manufactured in the West, but that one of SAAVI’€™s prime responsibilities would be to develop vaccines tailor-made for the viruses prevalent in South Africa as well as to keep the price down. – Health-e News Service.