Positive Vibes


The life cycle of HIV is carried out in 7 steps.

To better understand each step in the HIV life cycle, it helps to first imagine what HIV looks like.

HIV with labels

Now follow each step in the HIV life cycle, as the virus targets and destroys the CD4 cell.

HIV Life Cycle

1 Binding

HIV attaches itself to receptors on the surface of a CD4 cell.

2 Fusion

The HIV envelope and the CD4 cell membrane join together, which allows HIV to enter the CD4 cell.

3 Reverse transcription

Inside the CD4 cell, HIV releases and uses reverse transcriptase (an HIV enzyme) to convert its genetic material – HIV RNA into HIV DNA. The conversion of HIV RNA to HIV DNA allows HIV to enter the CD4 cell nucleus and combine with the cell’s genetic material – cell DNA.

4 Integration

Inside the CD4 cell nucleus, HIV releases integrase (an HIV enzyme) to insert its viral DNA into the DNA of the CD4 cell.

5 Replication

Once integrated into the CD4 cell DNA, HIV begins to make copies of itself by using the machinery of the CD4 cell to make long chains of HIV proteins. The protein chains are the building blocks for more HIV.

6 Assembly

New HIV proteins and HIV RNA move to the surface of the cell and assemble into immature HIV.

7 Budding

Newly formed immature HIV pushes itself out of the host CD4 cell. The new HIV releases protease (an HIV enzyme). Protease breaks up the long protein chains in the immature virus, creating the mature virus.