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Aids Vaccine Years Away From Production, Fund Warns

South African Press Association (Johannesburg)

June 2, 2003
Posted to the web June 3, 2003

Cape Town

The SA Aids Vaccine Initiative (SAAVI) cautioned on Monday that a "candidate" HIV/Aids vaccine developed by a team at the University of Cape Town (UCT) was still years away from human trials, let alone full-scale production.

Media reports on Monday morning painted a picture of an "Aids breakthrough" that was not altogether accurate, SAAVI's Michelle Galloway told Sapa.

The research was funded by SAAVI, a research funder set up by Cabinet in 1999 under the auspices of the Medical Research Council.

Galloway said the research product was presently only a candidate vaccine, meaning that while its laboratory research and development phase was now complete and positive results had been obtained in animal trials, it had not yet been tested on humans.

A small batch of the vaccine would next be prepared for toxicity testing and detailed documentation.

Approval would then have to be sought from the Medicines Control Council (MCC) in Pretoria and probably from the United States' Food and Drug Administration as well for further testing, Galloway said.

"If successful, approval for Phase One trials will be given.

That would involve a very small group of volunteers, healthy HIV-negative adults, to gather safety information on the vaccine.

"If successful, Phase Two would involve 200-500 HIV-negative, otherwise healthy adults to capture more safety data as well as immune responses and determine the best way to administer the vaccine," she said.

Only if that was successful would large-scale efficacy trials be held to "test the vaccine in a real-life situation."

Phase One typically lasted a year to 18 months, Galloway said, with Phase Two lasting a similar length of time and the third phase around three years.

As a result, the vaccine, provided it passed the many hurdles put before it, would only near readiness for registration with the MCC as a vaccine in about a decade.

Last September, SAAVI said three local candidate HIV/Aids vaccines were showing promise in laboratory testing.

"These vaccines will soon enter the manufacturing process and safety testing that precedes human clinical trials," it said at the time.

The three candidate HIV/Aids vaccine products incorporated the genetic sequences of South African strains of HIV (subtype C), the most prevalent strain in the region.

It was hoped that they would prove safe for use in humans and induce immune responses, and eventually show some protective properties in humans.

All three candidate vaccines were developed by UCT's Institute of Infectious Disease and Molecular Medicine and were being readied for low-rate initial production in a manufacturing plant that could produce the products in a manner suitable for initial human clinical trials.

SAAVI said the National Institute of Allergy and Infectious Diseases, the lead institute of the US National Institutes of Health for HIV/AIDS research, last year agreed to support the low-rate initial production of these vaccines at a cost of approximately R20-million. SAAVI would contribute a further R10-million.

The scientists at UCT, led by Professor Anna-Lise Williamson and Professor Carolyn Williamson have received SAAVI funding since 2000 to produce a series of "novel potential HIV vaccines."

Funding was also received from the government's Technology for Human Resources in Industry Programme, the International AIDS Vaccine Initiative and the Poliomyelitis Research Foundation.

The vaccines that have been developed by the SAAVI/UCT group include two "DNA vaccines" which express different HIV proteins; and, one "MVA (Modified Vaccinia Ankara) vaccine".

MVA is a weakened, safer form of the old smallpox vaccine which has been genetically engineered to produce HIV proteins in addition to its normal set of proteins.

The UCT scientists planned to test the vaccines individually and in combination, with the DNA vaccine used to "prime" or stimulate initial immune responses, followed by a MVA vaccine which aimed to "boost" this anti-HIV immune response.

SAAVI is tasked with developing an affordable, effective and locally relevant preventative HIV vaccine for southern Africa.

It annually awards funding amounting to multiple millions of rand to South African research groups at leading institutions to develop and test candidate HIV vaccines.

It also funds researchers investigating the ethical issues involved in testing HIV vaccines, and a community education project.

"SAAVI has developed into a sophisticated, national biotechnology consortium which operates at the cutting edge of international HIV vaccine development," SAAVI director Dr Tim Tucker said last month on the occasion of World Aids Vaccine Day.

"The growth of the initiative has exceeded the expectations of stakeholders and participants, with SAAVI products now in manufacture; clinical trial sites ready to test products; community, ethical and human rights issues carefully considered; immunology testing facilities developed which rival the best in the world; and, researchers occupying many senior international leadership positions."