Acyclovir fails to prevent HIV transmission Living with AIDS # 389
Acyclovir, medication used to treat herpes, has no effect on preventing HIV transmission, according to a new study.
Acyclovir suppresses genital herpes in both HIV-infected and uninfected people and reduces the frequency of genital ulcers, a common occurrence in HIV-positive people. Five recent studies have also shown that treating genital herpes using Acyclovir in people co-infected with HIV reduces both the genital herpes viral load and that of HIV. That led researchers to test whether the use of the drug itself could reduce chances of an HIV-positive person passing on the virus to their HIV-negative partner. They also tested whether Acyclovir delayed HIV disease progression in those who have HIV. The study involved nearly 3 500 sero-discordant couples, meaning one partner had HIV and herpes, while the other partner had no HIV. It was not a pre-requisite, however, that the uninfected partner should have herpes. The HIV-positive partner was healthy and not yet on ARVs. It was a randomized trial where half the participants received the active drug and the remainder received a placebo. The study results were announced by Dr Sinead Delany-Moretlwe of Wits University’s Reproductive Health and HIV Research Unit (RHRU) and investigator in the Soweto site of the international trial.
‘The key result is that Acyclovir suppression did not reduce HIV transmission. There were 136 HIV transmission events and about 84 of them were linked ‘ and by that we mean laboratory testing was able to confirm that the infection seen in the previously uninfected partner was transmitted by the infected partner. The rate of infection was equal in both study arms. There was no difference by treatment arm’, she said.
Although the key result was disappointing, Delany-Moretlwe said the study suggested some evidence that the use of Acyclovir in people co-infected with genital herpes and HIV, but who have a relatively healthy CD4 cell count could delay the growth of HIV in their bodies.
‘Acyclovir had an impact on the levels of HIV in blood and reduced HIV levels by 0.27 or a quarter of a log’, she said.
‘That’s a 40% reduction. Antiretroviral treatment would have reduced that from 10 000 to less than 50, which we call undetectable. This is a modest decrease in viral load’, added Dr Andrew Mujugira, Director of the study in southern Africa.
But the result is not yet conclusive, warned Delany-Moretlwe.
‘We are cautious about interpreting the impact on HIV disease progression at the moment. I think it’s an exciting result. It’s modest. And what we want to investigate is whether greater gains can be achieved with better drugs. We also need to understand whether there are any risks involved in providing HIV-positive people widely with Acyclovir because of concern about potential emergence of HIV resistance.
And there’s also a cost-effective analysis to be done because, perhaps, resources could be better used (by) just initiating people on to treatment earlier rather than gaining a little bit of time by putting them on Acyclovir. I think those questions still need to be researched before we can change policy’, she explained.
The study was dubbed the ‘Partners in Prevention Trial’ and was conducted in 18 sites in southern and east Africa. In South Africa there were three sites in Soweto and Cape Town.