Almost every month we hear of a new drug or some other treatment for HIV infection on television or in newspapers. 'Treatment breakthroughs' reported in the media are often exaggerated and premature.

Any new treatment, no matter how promising it appears to be in laboratory tests, has to go through a careful process of clinical trials in people before its usefulness can really be known.

A clinical trial is a research study used to assess the benefits and risks of a new treatment. It is now widely agreed that a properly conducted clinical trial is the only way to prove that a treatment is effective.

Major advances in HIV therapy have been the result of clinical trials. For example:

• The Delta study showed that dual combination therapy with AZT/ddI or AZT/ddC prolonged life and delayed the onset of AIDS compared with AZT alone.
• The ACTG 320 study showed that triple therapy with AZT/3TC/indinavir was more likely to prolong life and reduce symptoms than AZT/3TC among people with CD4 counts below 200.
• The ACTG 076 study showed that AZT treatment during pregnancy, labour and the infant's first weeks of life can reduce the risk of HIV transmission from mother to child by two-thirds.
• The 006 study showed that a combination of the non-nucleoside efavirenz with AZT/3TC was superior to indinavir, AZT and 3TC over three years in terms in terms of the percentage of people maintaining viral suppression.
• The MS98-896 study showed that lopinavir boosted by a small amount of ritonavir achieved more durable suppression of HIV than the unboosted nelfinavir.
• The APRICOT study showed that treatment with a combination of pegylated interferon and ribavirin was the best option for hepatitis C virus infection in HIV-positive people.
•  The SMART study which showed that people who took CD4-guided treatment interruptions were more likely to develop HIV-related illness and some other illnesses than people who took their HIV treatment continuously.