Eradicating HIV/AIDS

15 January 2009

Dr Reuben Granich talks to George Marangos-Gilks about a new scientific hope

When you ask someone in the street the best way to cure AIDS – or any infectious disease for that matter – the answer you will get is vaccination. Prick everyone with a magic needle and within a generation AIDS is gone. Brilliant. The sooner a vaccine is found the sooner we can put an end to the estimated 2.7 million new infections that occur each year.

But the dark truth is that no vaccine is available, nor is one likely to be developed in the near future. Indeed, many people believe this to be an impossible task. The current best hope has just been withdrawn from trials for safety reasons and there is little else on the horizon.

Yet there is an alternative approach. The sexual spread of AIDS always involves two parties; an infected person passes on the disease to someone that didn’t have it before. It is obvious to all that preventing transmission is the only way to stop the disease.

Contrary to popular belief, there are many ways to go about this. Preventative vaccination focuses on the un-infected, aiming to make everyone immune to infection.

The alternative approach is to focus on the infected; to medicate the infected person so as to render them non infectious.

When someone is being treated for AIDS they are given antiretroviral drugs (ARV’s) to bolster their immune system and to prolong their life expectancy. Yet, importantly for prevention, the ARV’s also have the effect of lowering the virus enough in the infected person to prevent it being transmitted.

Thus in theory if all infected persons were immediately put on ARV treatment, the rate of infection would plummet and the spread of AIDS could very quickly be brought under control. A theory is all well and good but could this work in reality? A recent paper by Dr Reuben Granich and his colleagues at the World Health Organisation (WHO) suggests it could.

I met Dr Granich in Geneva. He began modestly, telling me that he and his team do not deserve all the credit for this idea.

“Science is a process in which you build on the ideas of others,” he said. “We have basically taken the current pieces and put them together in a unique way.

“For example, the concept of using antiretroviral treatment (ART) for prevention is well established. It has been hugely successful in the United States in preventing HIV transmission from mother to child. Women there are almost universally tested and those found to be infected go on to ARV treatment. The result is their babies are born free HIV. This is a strong case in point; we know the benefits, we know ARV treatment can prevent transmission.”

“Also, the concept of scaling up treatment to help prevent transmission is not new. It has been researched and modelled by other scientists. The difference with our study was that we freed our minds from the constraints of only giving treatment to people who are immunologically compromised.

We decide not to wait until people showed signs of sickness before putting them on treatment and we combined this with regular testing of individuals once a year. Basically we wanted to see what would happen to transmission rates if we could get as many infected people on ARV treatment as soon as possible.”

Dr Granich and his colleagues took data from studies in several African countries, and created a computer model which predicted that infection rates would in fact decrease dramatically.

The rate of new infections (currently 20 people per 1,000 each year) would fall within ten years of full implementation to one per 1,000 per year. Within 50 years the prevalence of HIV would drop below 1% compared with up to 30% at the moment in the worst-affected areas.

“Obviously there are a number of feasibility issues and these cannot be resolved over night,” Dr Granich said. “But within five to ten years we should have key answers to many of the questions needed to potentially implement this strategy in a number of places.

“If the upcoming field research supports our theoretical model, I’m confident that given the resources, and the right geo political context, there is a real possibility that we can achieve the predicted 95% reduction in HIV transmission.”

He continued: “The question is really what now? Where do we go from here? We need to further build up the evidence base to prove that this is a viable option. Achieving universal treatment would be a huge undertaking but we know we have the ability to test large numbers of people.

“We also know we have the ability to hand out ARV treatment. All of this was doubted at one time but we have achieved it. There are now 3 million people on ARV treatment and UN AIDS already has a goal of universal treatment. So it’s just a question of a massive scale up.”

We moved onto the ethical issues that this sort of prevention strategy raises.

Conventionally, those with HIV are only started on ARV treatment once they start to show signs of illness. This is often years after the initial infection.

The current wisdom goes that there is no need to start people on the medication before they show signs of illness because ARV’s brings little clinical benefit while often inducing undesirable side effects such as nausea, vomiting and diarrhoea.

Given this line of argument I can understand the controversy in forcing people to begin treatment as soon as they are diagnosed.

Indeed, governments and agencies are left with a very difficult question: is it justified to violate the rights of an infected person by forcing them to undergo unpleasant and unnecessary treatment if this brings an overall net benefit to the community?

This said, it should be noted that recent studies are challenging the conventional wisdom that there is little clinical benefit to be gained from early ARV treatment.

Dr Granich said: “Studies are suggesting that HIV is damaging regardless of whether you are feeling ill or not. It appears that HIV may damage your heart, kidney and liver, even encourage cancer long before we see immune system decline. None of these are conventional AIDS symptoms (those that make you feel sick and prompt you to take medication) but they are damaging nonetheless.”

The Economist mentions a recent study in support of this. Its findings suggest that delaying treatment until classical symptoms occur increases someone’s chances of dying by up to 70%.

Dr Granich said: “I won’t go into the technicalities but there are a number of arguments that suggest that starting treatment early brings benefits to the individual as well as to the community. Even if there was only an 80% chance that early medication would be beneficial I think most people would go for it because there is a very strong sense of community out there.”

“As long as the individuals and community are part of the process, are clear on the potential benefits and the program is 100% voluntary then I have no ethical qualms with early treatment. It shouldn’t need to be coercive, there are strong enough reasons, both individual and communal to persuade people to take up early ARV treatment.”

I ended by questioning Dr Granich’s commitment; if he eradicated AIDS then he would be out of a job.

“That would be great,” he said. “I would love more than anything not to have to work on HIV any more. AIDS is such a terrible disease. I’ve seen so many friends and patients die from it. It’s awful. This is a serious business.

“People will look back and judge us in 50 years and say – what did these people do to stop this? I’d like to say that I did all I could.”