Monday October 8 10:10 AM ET

AIDS Vaccine Seen Within Reach in Next Decade

By Victoria Thieberger

MELBOURNE (Reuters) - Scientists are increasingly optimistic that an AIDS vaccine will be available in the next 6 to 10 years, although the first one may not be 100% effective, researchers said on Sunday.

And because the design of any ultimately successful vaccine is not yet known, the cost could vary from a few pennies per dose to US$100 or more, affecting the vaccine's take-up in the developing countries that are worst hit by AIDS and HIV--the virus that causes AIDS.

The 6th International Congress on AIDS in Asia and the Pacific was told that results from the most promising trial so far could be available as early as next month.

"There's never been more optimism than there is now that an HIV vaccine can be identified,'' said Margaret Johnston, assistant director for AIDS vaccines at the US National Institutes of Health.

"There are many designs that have proven highly successful in animal models and we have a vibrant pipeline of products that are now being tested,'' she said on the second of a 5-day conference. "I have enormous confidence there will be a vaccine.''

Johnston said the leading vaccine candidate, VaxGen Inc.'s AIDSVAX is in the final phase 3 stage of clinical testing and interim results from its North American testing could be available as early as next month.

The protein agent, which is also being tested in Thailand and the Netherlands, works by inducing antibodies to help repel HIV.

The race to find a vaccine, which began soon after AIDS was first identified as a disease in the early 1980s, has produced more than 90 candidates that are now being tested on humans in the hope of halting a worldwide epidemic that has killed 22 million people and has infected 36 million others.

About 7 million people in Asia live with HIV/AIDS, while an estimated 500,000 people die of the disease each year.

Another promising vaccine candidate, Aventis SA's ALVAC, is in phase 2 testing and could progress to the final stage in the next year or 18 months. Several candidates are in early phase 1 trials and there is a long list of potential candidates in pre-clinical development.

"The soonest we can have a vaccine is maybe 4 to 5 years from now and that is wildly optimistic,'' Johnston said, saying 6 to 10 years was a more likely time frame.

"And the chances are the first one we identify will not be 100% effective.''

But even a low rate of effectiveness will help control the spread of HIV, while further improvements to the design could help improve its efficacy.

Production costs will depend on the design of the vaccine, with a DNA-based product costing from a few pennies to a few dollars, while a recombinant product requires a more high-tech process in manufacturing and could cost tens of dollars or $100 or more.

Johnston said there would also be licensing costs since no single manufacturer would likely have all the patent rights necessary to produce a vaccine.

The conference, which has attracted about 3,000 scientists, health workers and activists from across the region, was also told the world risked being distracted from the fight against AIDS because of the September 11 attacks on the United States.

"The world is understandably deeply preoccupied with the events of September 11, but we cannot allow this tragedy and the shockwaves which follow to distract from HIV/AIDS,'' said former Australian ambassador to the United Nations Penny Wensley.