THIS is one of the most exciting times to be working in HIV medicine.
Initial results from an international, multicentre randomised study looking at the inferiority of delayed treatment for HIV — Strategic Timing of Antiretroviral Therapy (START) — were recently published in the New England Journal of Medicine
. They confirmed something many of us had thought for some time — that earlier HIV treatment is superior to delayed initiation of treatment.
START has caused a paradigm shift away from delaying treatment.
Until recently in Australia, medication subsidised by the Pharmaceutical Benefits Scheme (PBS) was only available to people with CD4 cell counts below 500
There was less tolerance to older HIV treatments, they had more side effects and were vulnerable to the development of resistance. With these drugs, a person who started treatment early might have exhausted their treatment options at about the same time as they would have, without treatment, started to develop HIV-related symptoms.
Contemporary treatments are streets ahead of their predecessors. Speaking at the close of the last Glasgow HIV Drug Therapy conference
, Dr Trip Gulick
indicated that a young person with HIV and on antiretroviral therapy (ART) should expect an equal to, or greater, life span than a non-infected peer, due to the linkage to care necessitated by ART.
New HIV treatments are far more tolerable, can be taken for extended periods and, if taken as prescribed, are more forgiving of the occasional missed dose, making them less vulnerable to the development of resistance.
The most exciting new development, however, is that a person on treatment with an undetectable viral load is virtually non-infectious. This will be one of the strongest tools in our armament against HIV transmission.
Prevention is also facilitated through the taking of HIV pre-exposure prophylaxis (PrEP) by those at risk of acquiring HIV. PrEP
is similar to malaria prophylaxis and involves taking medication before exposure to reduce the likelihood of HIV acquisition. As with malaria prophylaxis, it is recommended that other steps are also taken to reduce exposure, particularly the continued use of condoms.
These two approaches, along with increased and more effective testing, should really see a significant change in the HIV outlook: driving down new infections by rendering people on treatment non-infectious and protecting those at risk of HIV acquisition through the addition of a chemotherapeutic barrier.
There are, however, a number of complicating factors which will first need to be overcome to realise such a change.
Cost is the single most restrictive factor limiting the use and uptake of PrEP. In Australia, people with HIV, regardless of their CD4 cell count, have access to treatment through the PBS. However, PrEP, which uses a combination of two antiretroviral drugs, tenofovir and emtricitabine, costs more than $1000 per month.
PBS listing of this medicine would make this preventive measure largely accessible in the Australian community of people at high risk.
Attitudes toward PrEP present a far greater barrier, with questions being asked about why such a costly alternative is necessary.
Relying on just condoms presents too many risks. Some older Australians who once had to rely on condoms for contraception, then obtain an illegal abortion or give up children for adoption, know the limitations of condoms as a prevention strategy.
Daily, oral contraception revolutionised family planning universally, but it was condemned by many when first introduced.
We are now seeing some negative attitudes toward PrEP from clinicians, HIV-positive people and some of those who lived through the early years of HIV. Perhaps this is out of concern for the losses and sacrifices made by others. But it does seem that these attitudes are changing, as they did towards oral contraceptives.
If PrEP were to cost the same as the oral contraceptive pill, I am sure people would be criticised if they were not using it.
A cure or vaccine for HIV is still a long way off. However, increases in testing and the demonstrated effectiveness of PrEP mean that it may be possible, one day, to virtually eradicate HIV using the tools we have.
Dr Levinia Crooks (AM) is the CEO of the Australasian Society for HIV, Viral Hepatitis and Sexual Health Medicine, and an adjunct associate professor of public health and human biosciences at La Trobe University, Melbourne.