PANOS Institute, London - Thursday, December 24, 1998
Martin Foreman

The vaccines will be the first to be developed specifically for the developing world, IAVI says. Despite the optimism, the fact remains that no vaccine will be available for at least a decade, researchers say. And many scientists remain concerned that ne ither vaccine may turn out to be effective in human beings. But the need for vaccine remains - there is no cure for AIDS and not enough people are using condoms or abstaining from unsafe sex to reduce the rate at which the virus is currently transmitted, estimated at 16,000 new cases per day.

A group of drugs, called anti-retrovirals, do manage to keep the symptoms at bay but, at an average cost of 8,000 dollars per person per year, they are way beyond the pockets of the millions of AIDS patients in the developing world. An effective vaccine is seen as not only a lifeline but also a way to reduce the heavy costs of AIDS - both in treatment and lost resources.

However, experts say many scientific and economic hurdles need to be crossed before a vaccine is made widely available in the developing world. Researchers have to ensure that the vaccine is safe, so that it does not lead to illness, and effective, prote cting the majority of those vaccinated. In addition, there are several different strains of HIV and vaccines developed to work against one may not necessarily protect against another.

The scientific problems create an economic one. The straitened economies of countries where AIDS is most widespread - in sub- Saharan Africa and South Asia - cannot afford costly mass-vaccination against strains A, C, D and E, which are prevalent in these regions.

At the same time, most of the current research is for a vaccine against strain B, which is common in North and South America and Europe.

Pharmaceutical companies are generally unwilling to pay for vaccine research unless they can recoup the costs through the finished product - so there is little market incentive for them to invest in vaccines which could be effective only in developing co untries.

It was with a view to overcome these obstacles that IAVI, a nonprofit scientific organisation, set up the joint groups - in South Africa and Kenya - as part of a strategy to encourage the simultaneous development of several 'candidate vaccines.'

"IAVI wants to accelerate the global effort to develop a vaccine through collaboration, not competition," said IAVI president, Dr Seth Berkley. "Our goal is not only to ensure the development of an AIDS vaccine as soon as possible. Our goal is to make it accessible to anybody in the world who needs it."

The South African initiative is a joint project between the University of Cape Town and the University of North Carolina, USA, with Alpha Vax Human Vaccines, a pharmaceutical company in Durham, North Carolina. The basic ingredient of this vaccine is a ha rmless form of Venezuelan Equine Encephalitis with genetic material from the C strain of HIV. Trials in mice and monkeys have proved successful but experts say changes need to be made before trials begin in humans.

The Kenyan initiative brings together researchers from the University of Nairobi, Oxford University in Britain and IDT, a German pharmaceutical. Here, the candidate vaccine uses MVA - a harmless virus used in smallpox vaccines - which is genetically simi lar to the A strain of HIV, common in Kenya. Trials in rodents and monkeys have also proved successful and these will be followed by a three-stage process of trials in humans - first in Britain and then Kenya.

Once initial trials have been carried out in the UK and Kenya to ensure the vaccine is safe, another phase of trials will begin in Kenya among commercial sex workers. "It is essential to carry out the trials in [countries like] Kenya because that is whe re the main need is. And the candidate vaccine must be tested in a high-risk group to see how effective it is," said Sarah Rowland-Jones of the Oxford group.

Dr Omu Anzala, a member of the Nairobi University team, said that a million Kenyans - 70 percent of those living with HIV in Kenya - have contracted the A strain.

"The important thing is that we have the biggest problem here and we cannot sit around and hope that someone will come to our mercy," said Anzala. "If we left it to pharmaceutical companies they would produce a vaccine which is only useful in North Am erica and Europe," he added.

Although the principle of vaccination against HIV is widely accepted, the absence of research on other HIV strains that are common in the developing world has led some activists in Africa and Asia to question the relevance of the trials in their regions. According to Berkley, previous groups have developed vaccines for B strains and tested them in developing countries with a view to manufacturing them in the North.

Nine other candidates are being monitored by IAVI, but they are all designed to protect individuals from contracting the B strain, which is rare in Africa and Asia. Three of them may also be effective against the E strain - found in East Asia and the Pac ific. But no candidate vaccine is being developed to protect against the D strain, common in Africa.

On the other hand scientists believe trials in developing countries - where people are more likely to contract AIDS - are the only effective way to test the vaccines.

IAVI have already signed pricing agreements with Alpha Vax Human Vaccines and the Medical Research Council in Britain, under which companies can only charge for the cost of production plus a maximum 10 percent in profit. If the vaccines can be produced m ore cheaply elsewhere, IAVI can force the companies to move their production to those countries. This applies to sales in developing countries only.

This, according to Berkley, is unique. Usually vaccines are sold in the North for 10 to 15 years, during which time pharmaceutical companies recoup their costs. It is only after this that they begin trickling into Southern markets. A further idea apparently being considered is for pharmaceutical companies to hand over some of the intellectual property rights of the vaccines to developing countries in exchange for permission to hold trials. This could allow countries to produce vacc ines locally and more cheaply.

"We have to push this idea very carefully," cautions Dr Jose Esparza, leader of the vaccine team at UNAIDS, the AIDS branch of the United Nations. "We don't want to create more disincentives to pharmaceutical companies."

"At the end of the day," Esparza added, "the poorest countries will have to be subsidized if they are going to be able to buy an AIDS vaccine." Editor: Dipankar De Sarkar. Please credit Panos when using these features.

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