Search for AIDS cure to be intensified

Search for AIDS cure to be intensified

The search for an AIDS cure will be intensified, according to the International AIDS Society (IAS), which yesterday published its cure strategies and priorities.

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Credit: Health24.com
Credit: Health24.com

The action plan for “one of the most important global health goals of our time – a cure for HIV”, was published yesterday evening by respected journal Nature Medicine.

“Not long ago, few considered the possibility that a cure for HIV infection could some day be possible,” said Françoise Barré-Sinoussi – who co-chairs the IAS’ “Towards an HIV Cure” Initiative.

But thanks to a handful of high priority cases where patients were cured or could control the virus after treatment (see BOX), she said “the search for a cure has become a top priority in HIV research”.

“Today, thanks in part to advances such as the cure of an HIV-infected individual through a stem cell transplant, the identification of a small cohort of individuals who are able to control infection following treatment, and some noteworthy advances in cell, gene and immune therapy, the search for a cure has become a top priority in HIV research,” said Barré-Sinoussi, a French virologist, was awarded the Nobel Prize for medicine for her work that led to the identification of the HI virus.

Research milestones towards a cure

Some of the key progress made in HIV cure research over the past three years and analysed in the new strategy include :

  • Sustained periods of aviremia (no virus in the blood) in the absence of anti-retroviral therapy (ART) achieved in an HIV positive baby who was initially aggressively treated with ART, in at least two individuals who have received stem cell transplants, and in adults who received several years of ART initiated soon after infection.
  • Evidence that early initiation of ART limits the establishment of a “reservoir” of HIV in the body.
  • The development of new tools that can quantify the frequency of a cell that carries replication-competent virus,and the demonstration that some biomarkers can predict the time to viral rebound following treatment interruption.
  • Evidence suggesting that HIV continues to replicate and evolve during the first six months of ART but not necessarily during long-term ART.

Future cure not a substitute for current strategies

However, according to Professor Francois Venter, from the University of the Witwatersrand’s Reproductive Health and HIV Institute, we cannot rely on a cure to see an end to Aids.

“I do worry that an HIV cure is a huge scientific challenge that will take a long time to achieve while HIV treatment is currently so effective – we need to stay focussed on getting treatment to all,” he said.

Although funding for cure research is steadily increasing with US$201.8 million being spent in 2015 versus US$160.8 million in 2014, the global community is not waiting for a cure to beat the epidemic and has set ambitious targets to end Aids by 2030 – an agreement signed by United Nations (UN) member states in the beginning of June.

This target hinges on another UN goal – the 90 90 90 strategy: by 2020, 90 percent of people with HIV should be aware of their status, 90 percent of HIV-positive people should be on treatment and 90 percent of those on treatment should be virologically suppressed (when the amount of the virus in the blood is so low it is undetectable).

Universal test and treat programme

In line with these aims, and advice from the World Health Organisation, Health Minister Aaron Motsoaledi announced in May that by September this year all HIV positive South Africans will be eligible for treatment – under a universal test and treat programme – instead of having to wait for their immune levels to drop.

People on treatment whose viral loads are undetectable are not infectious so the strategy is aimed at significantly stemming new infections while improving health and prolonging lives.

But, according to the Treatment Action Campaign’s Marcus Low, “talk of an ‘end to Aids’ is premature”.

“The available data seems to suggest that South Africa will struggle to reach the second two 90s by 2020,” says Low. “This doesn’t mean it’s not a useful target to have but it means that there is no room for complacency.”

Testing still a problem in SA

Venter said that even reaching the first 90 target – testing 90 percent of people with HIV – will be difficult for the country.

“We’re nowhere close to reaching the first 90 as between 40- and 50 percent of the population haven’t tested for HIV. It’s a disaster we need to address by dramatically escalating HIV testing programmes.”

While South Africa has the biggest HIV treatment programme in the world, with 3.4 million people on ARVs, more than half of the country’s HIV positive population are still untreated.

Venter said that “encouragingly”, those who have been tested and are on treatment seem to be doing well.

“We’re nowhere close to reaching the first 90 as between 40- and 50 percent of the population haven’t tested for HIV. It’s a disaster we need to address by dramatically escalating HIV testing programmes.”

“It’s a commonly cited problem – that South African HIV patients aren’t virologically suppressed – which is untrue in many parts of the country with access to ARVs,” he said.

According to Venter, many places where viral loads are monitored show close to 90 percent of South Africa’s HIV patients on treatment are virologically suppressed, which means they are taking their medication correctly and it is working for them.

Differences between women and men

“What is worrying is that women are getting to 90 percent but men are not. They are dragging the numbers down to well below 90, for testing as well as treatment.”

He said more programmes directed at men are needed to ensure testing and adherence.

“We have many programmes targeting women but there is a serious shortage of ones targeting men – who we see are more likely to fail HIV treatment,” he said.

As South Africa gears up to host the 21st International Aids Conference in Durban next week, former head of the Human Sciences Research Council and conference co-chair, Dr Olive Shisana said that she fully supports the IAS’ roadmap to find a cure. “Despite our gains, much more needs to be done,” she said. “Progress is precarious – we need a cure.”

Outgoing IAS president Dr Chris Beyrer said the strategy is “an invaluable roadmap that will help us take cure research to the next scientific level”.

 

BOX

One patient cured of HIV – ever

Only one individual has successfully been cured of the virus. Colloquially termed ‘the Berlin patient’, as he lives in the German city, Timothy Ray Brown remains the only human on the planet who has been completely cured of Aids.

In 2006, after living with the virus for 11 years and controlling it with daily doses of antiretroviral drugs, Brown was diagnosed with an aggressive form of leukaemia. In 2007, after chemotherapy failed he received another therapy common for this kind of cancer – a bone marrow transplant. For the past nine years Brown has stopped taking his ARVs which in normal cases would lead to a dramatic escalation of the amount of virus in the blood, but in his case did not.

Researchers believe Brown was cured because he received his bone marrow transplant from a donor who had a rare genetic mutation making them naturally resistant to HIV.

There have been a handful of other cases of people being “cured” of HIV. but in most cases the virus came back after a period of time.