Clinical trial results hailed as ‘an extremely important breakthrough’ in HIV prevention, reports BILL CORCORAN in Cape Town
THE EARLY treatment of HIV positive people with antiretrovirals (ARVs), a combination of drugs designed to control the virus, reduces the transmission rate via sexual activity by 96 per cent, an international clinic trial has found.
Announced simultaneously at a number of different locations around the world early this month, the trial results were hailed as “an extremely important breakthrough” in the field of HIV prevention by Dr Guy de Bruyn, a principal investigator for the study in South Africa.
Aids activists have begun urging donor nations to increase their spending on ARVs so that the drugs can be administered in line with the study’s findings.
However, the global economic recession has taken its toll on the ability of some countries to increase spending on the fight against a disease that affects 33.3 million people worldwide.
The US, England and other donor countries have already indicated they will be opposing firm Aids treatment targets at a UN meeting in New York on the issue next month where it was hoped 15 million sufferers could be put on ARV treatment by 2015.
A report released last week by medical humanitarian organisation Médecins Sans Frontières (MSF) revealed that several countries hardest hit by the Aids epidemic are already finding it difficult to introduce earlier HIV treatment due to a lack of financial support.
“Our report shows that there is clear engagement from countries to providing an ambitious response to Aids, by changing their guidelines to put people on treatment earlier and with better drugs,” said Dr Tido von Schoen-Angerer, executive director of MSF’s Access Campaign.
“But because of funding constraints, some of them are unable to put these guidelines into practice, which serves as a reminder of how fragile this progress really is,” she said.
The ground-breaking study, which began in 2005, involved more than 1,763 couples in 13 study locations around Africa, Asia and North and South America.
Known as HPTN 052 study, the US National Institute of Health-funded trial was due to end in 2015, but it was halted early because of the overwhelming evidence of benefits following recommendations by an independent data and safety monitoring board.
One person in each of the participating couples was HIV positive while the other was not infected with the disease.
When they enrolled in the study, each HIV-positive partner had CD4 cell counts – a measure of a person’s immune system – of between 350 and 550, which under the UN World Health Organisation’s recommendations means they are not eligible for treatment with ARVs.
To date HIV-positive people were usually put on ARVs only when their immune system had weakened considerably due to the risk of resistance to the drugs and the toxic effect on the body.
For the purposes of the trial, couples were randomly assigned to two groups. In the first group, the HIV-positive partner was given ARVs when the CD4 cell count fell below 350, and the virus was beginning to damage the immune system.
In the second group, the HIV-positive partner started on the ARVs immediately, regardless of how damaged their immune systems were.
“The results are an extremely important breakthrough in the field of HIV prevention and conclusively demonstrate that treatment of the HIV-infected person reduces the chance they will transmit HIV to their negative partner,” Dr Bruyn said in a statement.
In South Africa, which has one of the highest HIV prevalence rates among its adult population in the world at 29.4 per cent, the study was co-ordinated by the Perinatal HIV Research Unit based at the Chris Hani-Baragwanath Hospital in Soweto, and at the Helen Joseph Hospital and the University of the Witwatersrand in Johannesburg.
“In all, 28 linked infections occurred in couples participating in the study,” the university said.
Only one of these infections was in a couple where the HIV-infected partner received early treatment. A further 11 infections occurred and were either not linked – the transmission did not occur from the HIV-positive partner in the study – or the investigations had not been finalised.
“All study participants received a comprehensive package of prevention services designed to reduce their risk of HIV infection throughout the trial, including HIV testing, intensive safer-sex counselling, provision of free condoms and treatment of sexually-transmitted infections,” the university added.