Two AIDS patients serve themselves food at an assistance center run by the Catholic charity Maryknoll on November 25.

Two centuries ago, the Spanish monarchy sent a group of orphans on a ship to its

colonies in the Americas. The children served as living vessels for the vaccine against

smallpox, the equivalent at the time of today's HIV, or AIDS virus.

Two children were vaccinated shortly before departure, and when pustules developed

on their arms, the ship's doctor would use some of the pus to inoculate two more

children, roughly every nine days.

There was no system of refrigeration to preserve the live vaccine during the long

voyage across the ocean to Spain's colonies. The experiment is considered the first

international public health operation.

Today, smallpox has been eradicated. But researchers are working hard to come up

with a vaccine of similar importance: one that will fight HIV, the AIDS virus, the

worst scourge in a century, which claims three million lives a year, the highest

rate ever.

The number of people living with HIV/AIDS-over 40 million today-is steadily climbing,

as is the number of deaths the virus causes, said Marika Fahlen, director of social

mobilization and information for the United Nations Joint HIV/AIDS Programme (UNAIDS).

Some five million people have been infected with HIV this year, said Fahlen at the

release of the annual report ''AIDS Epidemic Update 2003'' in London.

The disease appears to be unstoppable despite the barrage of efforts, which include

treatment with antiretroviral drugs, as well as prevention measures like educational

campaigns on safe sex and awareness-raising initiatives on how the virus is spread.

But the biggest hope lies in the discovery of a vaccine. Efforts towards that goal

have been under way since 1985, said José Esparza, a World Health Organization

(WHO) AIDS vaccine expert.

The provision of pharmaceuticals to people living with HIV/AIDS took on renewed momentum

through the WHO/UNAIDS strategy known as "3x5", shorthand for making the

antiretroviral "cocktail" therapy available to three million people in

2005.

Today, only 400,000 people receive the drugs, said WHO official Donald Sutherland.

Of that total, a relatively large proportion, around 70,000 live in South America,

mainly Brazil.

Esparza noted that, years ago, the Brazilian government began to furnish people living

with HIV/AIDS with antiretroviral drugs free of charge. The big challenge now is

to make these drugs available to patients in Africa, a moral commitment that the

world must assume, he said.

Science cannot continue producing wonder drugs that radically change the prognosis

for people living with HIV/AIDS in the United States and Europe, while the developing

world has virtually no access to those drugs, he argued.

Catherine Hankins, UNAIDS chief scientific adviser, points to the situation in sub-Saharan

Africa, which is dominated by a cycle of disease and death largely due to the total

lack of far-reaching prevention programs and antiretroviral treatment.

Of the 40 million people living with the disease worldwide, nearly 27 million are

in sub-Saharan Africa, amounting to between 7.5 and 8.5 percent of the adult population

on that continent.

Prevalence of the disease in that region ranges from less than one percent in Mauritania

to nearly 40 percent in hard-hit Botswana and Swaziland. But Esparza says the application

of the "3x5" strategy would renew hopes in Africa about the availability

of antiretroviral drugs and would revitalize programs for fighting HIV/AIDS in all

developing countries.

The price of these medicines today has dropped to the point that, with less than

a dollar a day, a person with AIDS can be treated with the least expensive yet appropriate

drug cocktail that the WHO recommends.

That sum is around 300 dollars a year, which is still considered high, but is a tiny

portion of the 10,000 to 15,000 dollars per person that the drugs cost just a few

years ago.

However, Esparza notes that the problem is not limited to prices, but also involves

the infrastructure needed to distribute the medicines. The treatments are complex

and require strict medical follow-up. There are many who say the African optimism

is a bit premature, he adds.

The big pharmaceutical transnationals used the same arguments in 2001 when debate

began on authorizing developing countries to produce generic versions of the drugs

in order to treat their ill, as Brazil, South Africa and India have done since.

With this panorama, Esparza says a vaccine to prevent AIDS is the best hope for definitively

controlling the epidemic.

But he admits that it is not easy, nor will a vaccine be available soon, as indicated

by the outcomes of two trials published this year.

In February, encouraging results were announced for tests involving 5,400 people

in the United States, using the first generation of what are known as the GP120 vaccines.

And a few weeks ago, reports were released for a similar trial conducted in Bangkok,

with 2,500 young men who use intravenous drugs. But the vaccine did not provide much

protection for high-risk populations.

Nevertheless, the experiments with vaccines have provided important lessons. For

one thing, they have shown that it is possible to follow the individuals taking part

in the trials for three years, even though they often live in difficult situations.

"We now know that the tests can be conducted with the highest ethical and scientific

standards," says Esparza.

But another issue is that the antibody induced by this type of vaccine does not protect

people who already have HIV, at least not for the majority of the test population.

A different kind of antibody is needed, and scientists are already trying to identify

one, said the WHO expert.

Another lesson is that in future experiments, variables of gender and race need to

be taken into account. Esparza admits that tests should include more women and more

people representing different ethnic groups.

On another front, some unpublished studies conducted in the United States show that

people of African descent produce higher levels of antibodies than people of European

descent. This phenomenon was unknown until just a year ago.

The relatively poor results of the two vaccines developed in the past three years

have prompted members of the scientific community to seek a different route.

In June, AIDS researchers proposed creating a global enterprise for a vaccine, based

on the model that was used to decipher the human genome.

The enterprise will be an alliance of research institutions, independent agencies

from developing and industrialized countries alike, both public and private sector-and

would include the WHO and UNAIDS.

The alliance, which is sponsored by the U.S.-based Bill and Melinda Gates Foundation,

is founded on the principle of a common scientific plan, says Esparza, who will leave

the WHO in the next few months to join the new project.-IPS

Facts about HIV/AIDS

Infection

ï In 2003, 5 million people are expected to contract HIV, a slight increase o ver

2002.

ï Infection rates are rising throughout sub-Saharan Africa, India and China.

ï Uganda, Thailand and Cambodia are among the only countries to have successfully

reduced their HIV prevalence rate.

ï Southern Africa, with less than 2 percent of the world's population, has about

30 percent of those living with HIV/AIDS.

Death toll

ï About 8000 people succumb to the virus every day worldwide.

ï 68 million are expected to have died by the year 2020.

ï 26 million people have already died from AIDS since 1980.

ï There are at least 40 million people living with HIV/AIDS worldwide.

Treatment:

ï In 2003, the least expensive drug regime approved by WHO cost about $300 per year.

ï In 2000, the standard drug regime in developed nations cost between $10,000 and

$12,000 per year.

ï Last year, about 800,000 people had access to anti-retroviral treatment for HIV/AIDS.

ï 500,000 of them lived in high-income nations.

ï 50,000 and 43,000 lived in sub-Saharan Africa and the Asia-Pacific region, respectively.

Cambodia and Asia

ï In Cambodia, 157,000 people live with HIV or AIDS.

ï Over 1 million people are expected to acquire HIV in the Asia and Pacific region

in 2003.

ï 7.4 million people in the region now live with the virus.

ï 500,000 of them are estimated to have died of AIDS in 2003.

Sources: UNAIDS, WHO