Why is HIV difficult to cure?
Finding a cure for HIV is difficult for several reasons. Even with antiretroviral treatment (ART), some HIV remains hidden in the body in what is known as 'reservoirs' that ART cannot reach. Scientists are still trying to find out how to find these reservoirs and develop a treatment that can clear them.
How does HIV make copies of itself?
To make new copies of itself HIV has to go through a certain process. This process is often divided into 5 steps, which are outlined below.
1. Binding and fusion
HIV uses your body's CD4 cells to make copies of itself. To do this the virus has to get inside the cell. In the first stage of the process, HIV attaches itself to a CD4 cell. Once HIV is attached, it fuses with the outer layer of the CD4 cell. This opens the cell up so that the inner parts of the virus can get inside.
2. Reverse transcription
HIV contains a set of instructions with all the information on how to make more HIV. This is called RNA. CD4 cells cannot read RNA instructions. For CD4 cells to be able to read and understand the HIV's instructions, it has to be 'translated' into DNA, the language that the cell uses. Once inside the cell, HIV translates the RNA instructions into DNA.
For CD4 cells to be able to act on the new instructions, the HIV DNA has to get into the nucleus of the cell. The nucleus of the cell acts as the cell's brain, controlling what it does and how it behaves.
Once the HIV DNA gets inside the nucleus, it overwrites the cell's DNA. This means that instead of doing what the cell normally would, the CD4 cell now has to do what HIV tells it to. From this point on HIV can control the CD4 cell.
Once HIV is in control, it forces the cell to make the different parts needed to form a new HIV. The cell makes copies of all the different proteins and enzymes that are needed to form the new virus.
5. Assembly and budding
Once all the parts needed for a new HIV have been made, they gather together by the outer edge of the CD4 cell. They're then pushed out of the CD4 cell and released into the bloodstream, where they find a new CD4 cell to infect so that they can start the process again.
This is what happens when you're not on treatment. Taking antiretroviral treatment (ART) stops this process. Your ART contains a combination of drugs, each of which targets and prevents a different step in the process from happening. This keeps your viral load low and protects your immune system.
What is a drug interaction?
Some drugs shouldn't be taken together. This is because when taken together, they work differently and can have a damaging or dangerous effect on the body.
Some interactions can make the effects of your medication stronger, which can give you bad side effects or toxicity - where the increased amount of a drug in your body can cause harm. Other interactions can reduce your medication's effectiveness, meaning that your dosage isn't high enough to keep you well.
Sometimes drugs can impact on other health conditions you have, so you should let your healthcare worker know if you are managing any other health issues, such as liver problems.
Tell your healthcare worker if you take other drugs, herbal remedies or have other health conditions so that they can understand how these might affect your treatment.
How quickly will treatment start to work?
Antiretroviral treatment (ART) starts to work from the first dose on the first day. Your viral load drops quickly in the first week of starting ART, with some people reducing their viral load by 90% in the first 7 days. With good adherence, your viral load should continue to fall steadily from this point on. Over time, as your viral load becomes lower and lower, the speed at which your viral load drops will slow down. With proper adherence, many people will achieve a suppressed viral load within 6 months.
How quickly your viral load drops can depend on other health factors, for example, if you are managing any other infections at the same time. To achieve the best results the most important thing is that you take your antiretroviral treatment as prescribed by your healthcare worker.