How does HIV work?

HIV is a tiny virus that can only survive in the human body. It attacks a particular immune cell – the CD4 cell – that alerts other immune cells to any dangerous intruders.

If HIV enters your body, this happens:

he virus attaches itself to a CD4 cell 

The virus enters the CD4 cell
 

The cell produces new HIV particles

The new virus copies leave the cell and attack other CD4 cells

The virus converts its RNA into DNA and adds this to the CD4 cell’s DNA

The first CD4 cell is usually destroyed

HIV uses the CD4 cell as a photocopier.

The virus converts its own DNA (called RNA) into the cell’s DNA. The cell then goes on to produce new HIV particles. After the virus replication, the CD4 cell usually dies. Because the virus becomes part of the cell’s DNA, other immune cells no longer recognise it as a dangerous intruder. That’s how HIV can keep on using new CD4 cells to replicate itself. 

When a person has no more CD4 cells, they are susceptible to other viruses, bacteria and fungal infections. People with HIV then become ill and go on to be diagnosed with AIDS.