Antiretroviral drugs have been an astounding success, reprieving people with HIV from the brink of death and allowing them to live fuller lives. Although the roll-out around the world has saved lives and removed the distressing pictures of wasted AIDS victims from TV screens, experts know the drugs will not end the epidemic. The hunt is on for a cure, but it is proving tough.
Antiretroviral drug therapy suppresses the virus to such low levels that people with HIV are no longer infectious, but the drugs cannot get rid of the virus.
The virus has survived virtually everything that has been tried so far to eradicate it. It evolves quickly and efficiently if not completely suppressed — if somebody forgets to take their pills or runs out, for instance — and becomes resistant to the triple-drug regimen the patient is on. A new combination is then needed. Some people — for instance those born to mothers with HIV years ago before there were drugs to stop transmission at birth — have been through many.
“Some people in their late teens and early 20s have been through everything,” said Jane Anderson, an HIV consultant at Homerton hospital in east London. “They have been through masses of drugs.”
Fortunately, drug companies keep making new versions of the old ones, but there are no new classes of treatments coming along.
“At the moment it’s OK, but they have still not got huge options waiting around the corner,” she said.
Campaigners and HIV scientists talk of treatment as prevention. Studies have shown that people on antiretroviral therapy are not infectious. It has also been shown that taking the drugs can protect an uninfected partner of somebody with HIV. It follows that getting drugs to more people helps prevent HIV as well as treat it.
Drugs are still a stop-gap, infections are increasing everywhere and the focus now of the scientists and doctors in the International AIDS Society, the leading professional HIV organization in the world, is to find some kind of cure — either complete or what they call functional — which would involve permanent suppression of the virus in the body. The efficiency of HIV, however, makes it a formidable foe.
The gene therapy trial at the University of Pennsylvania is likely to cause some excitement among the scientific community that is looking for new ways to tackle the virus, after many failures, especially in vaccine development.
The researchers appear to have found potentially a new way to suppress the virus, which involves priming the body’s own immune system to keep it at bay.
This is not a cure, as it stands, but could be another option for those sentenced to a lifetime of drugs. It will also teach scientists more about HIV’s behavior and suggest new ways to attack it.
Hopes that bone-marrow transplants per se might clear the virus were dashed in December last year. Two people, known as the Boston patients, who were HIV-positive and received bone-marrow transplants were thought to be virus-free. They had no detectable HIV in their body and stopped antiretroviral therapy. However, after several weeks, the virus came back. Both are now back on drugs and said to be doing well.
One other recent remarkable case is that of a Mississippi baby, born in May 2010 to a woman who had not seen a doctor in her pregnancy and did not know she had HIV. Hannah Gay, associate professor of paediatrics at the University of Mississippi Medical Center, who saw the baby at 30 hours old, ordered tests that showed the baby had the virus and immediately gave the full three-drug treatment course.
There is speculation that the developing immune system of a newborn may be capable of clearing the virus whereas an adult’s is not.
These successes are limited, but they give hope to scientists and medical professionals that a cure is possible — one day.