Effectiveness of HIV therapy

Two and a half decades in to the HIV/AIDS epidemic, there have been major advances in HIV treatment and disease management. Perhaps the most important advance to date was the introduction of protease inhibitors in the mid-1990s, ushering in the era of highly active antiretroviral therapy (HAART) using combinations of drugs from different classes.

Modern combination HAART can suppress HIV viral load both in people new to therapy and in treatment-experienced patients, thereby enabling immune recovery. There are currently more than 20 approved antiretroviral drugs, and studies have shown that many combination regimens using different drug classes can produce good viral suppression. But antiretroviral therapy is not without its challenges, including drug resistance, side-effects, difficulty with long-term adherence and economic costs.

There remains some uncertainty about how long the benefits of antiretroviral therapy will last, given that people have been using HAART for at most ten years. To date, several ongoing studies have shown that effective therapy can keep HIV suppressed for years, especially in people starting treatment for the first time.

For patients who experience treatment failure, adding or switching drugs can often bring the virus back under control. New classes of drugs – including, most recently, CCR5 antagonists and integrase inhibitors – continue to be developed, along with an improved understanding of how best to use available therapies to achieve optimal outcomes over the long term. Since current therapies do not completely eradicate HIV, it is expected that for most patients treatment will be life-long.

Beyond improvements in laboratory measures of viral load and CD4 count, HIV treatment has dramatically reduced AIDS-related illness and death. As deaths due to AIDS have declined, there are now more people living with HIV, and the proportion of deaths due to other causes such as liver disease, cancer and cardiovascular disease has increased. While this is partly due to the fact that other chronic diseases have more time to develop as HIV-positive people live longer, antiretroviral drug toxicities may also play a role.

Unfortunately, not everyone has benefited equally from advances in HIV treatment. In developing countries, especially in Africa, a majority of people with HIV/AIDS do not have access to modern antiretroviral drugs. Even in industrialised countries, women and racial/ethnic minorities have not benefited to the same extent, largely due to poorer access to care. But studies show that with adequate funding and support, HIV treatment can be highly successful in resource-limited settings.