The trouble with HIV is that it’s so stupid

The trouble with HIV is that it’s so stupid… it’s smart! Owing to its own “design flaws,” the virus sometimes manages to outwit the drugs used to keep it under control. This has led researchers to develop sophisticated scientific methods for analyzing drug resistance, helping us to keep up with some of the treatment challenges that HIV can throw our way.

The HIV virus is a mindless little robot, programmed to do just one thing: make millions more copies of itself. Antiretrovirals, the drugs that fight HIV infection, are designed to interfere with this replication process and prevent the tide of new virus from being formed.

If HIV always made perfect new copies of itself, these drugs would actually have a much easier job. An antiretroviral drug would face the exact same task every time, so if one were effective, it would always be effective. Unfortunately, nature doesn’t work that way: HIV, being a little bit “stupid,” makes mistakes every time it builds a new virus. These mistakes, or mutations, lead to slight differences in every new virus. Sometimes these new, mutated viruses can resist the drugs that should be controlling them… making it difficult to find a drug combination that keeps working.

Resistance testing is a way of finding out which drugs are still likely to be effective against mutated strains of virus — and which ones will not work. Resistance testing is a rather complicated business, even for experts. Your inner science geek may be curious about how it works — it’s actually quite the story. More pragmatically, you should know when it’s important to have testing done and what the results can (and can’t) tell you.