Ask the expert

Q How close are we to finding a cure for Aids?

A News of a baby in the United States who was seemingly cured of HIV in 2013 made big headlines. While this offered hope, it did not translate into a cure.

About two years later, there were detectable levels of the virus in her blood. However, we remain optimistic that we will be able to develop a cure for HIV within the next few decades.

HIV, the virus which causes Aids, attacks the immune system itself - our very defence against infection. It infects key virus-fighting immune cells, such as CD4 cells, and then replicates itself in those cells by inserting its genetic code and killing the immune cell. This slowly weakens the immune system, leaving it unable to fight off other infections.

With antiretroviral therapy (ART), people with HIV can reduce the virus to undetectable levels in the blood. This enables the immune system to recover and function almost normally, and allows people with HIV to lead normal lives. It also significantly reduces the risk of transmission of the virus to others.

But it is not yet possible to clear the virus from every single cell in the body. This is because some cells are "dormant" or "resting" and can remain hidden, out of the reach of ART.

If a person with HIV stops taking ART, the virus "wakes up", multiplies and re-establishes itself. Efforts are now under way to find ways to eradicate these reservoirs.

The recent Joint United Nations Programme on HIV/Aids report highlights the next five years as a "window of opportunity" to enhance interventions to end Aids by 2030.

Early diagnosis, early start of treatment and the prevention of new infections are the cornerstones in the battle to halt Aids.

While great progress has been made in rolling out ART, the number of newly infected people is still increasing too fast, and access to treatment is not evenly spread, with often the poorest unable to get the appropriate treatment.

The report warns that if we do not address these issues now, we will never be able to halt HIV/Aids.

In Singapore, while the proportion of people with access to ART has improved greatly in recent years, many are still diagnosed late because of the stigma associated with a HIV-positive diagnosis.

  • Professor Annelies Wilder-Smith, Professor of Infectious Diseases, Lee Kong Chian School of Medicine, Nanyang Technological University
  • Have a burning science question? E-mail us at STscience@sph.com.sg
A version of this article appeared in the print edition of The Straits Times on July 24, 2015, with the headline 'Ask the expert'. Subscribe