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HIV Overview

The HIV Life Cycle

(Last updated 9/13/2016; last reviewed 9/8/2016)

Key Points

  • HIV gradually destroys the immune system by attacking and killing a type of white blood cell called a CD4 cell. CD4 cells play a major role in protecting the body from infection.
  • HIV uses the machinery of the CD4 cells to multiply (make copies of itself) and spread throughout the body. This process, which is carried out in seven steps or stages, is called the HIV life cycle. HIV medicines protect the immune system by blocking HIV at different stages of the HIV life cycle.
  • Antiretroviral therapy or ART is the use of HIV medicines to treat HIV infection. People on ART take a combination of HIV medicines from at least two different HIV drug classes every day. Because each class of drugs is designed to target a specific step in the HIV life cycle, ART is very effective at preventing HIV from multiplying. ART also reduces the risk of HIV drug resistance.
  • ART can’t cure HIV, but HIV medicines help people with HIV live longer, healthier lives. ART also reduces the risk of HIV transmission (the spread of HIV to others).

Once a person is infected with HIV, the virus begins to attack and destroy the CD4 cells of the immune system. CD4 cells are a type of white blood cell that play a major role in protecting the body from infection. HIV uses the machinery of the CD4 cells to multiply (make copies of itself) and spread throughout the body. This process, which is carried out in seven steps or stages, is called the HIV life cycle.

What is the connection between the HIV life cycle and HIV medicines?

Antiretroviral therapy (ART) is the use of HIV medicines to treat HIV infection. HIV medicines protect the immune system by blocking HIV at different stages of the HIV life cycle.

HIV medicines are grouped into different drug classes according to how they fight HIV. Each class of drugs is designed to target a specific step in the HIV life cycle.

ART combines HIV medicines from at least two different HIV drug classes, making it very effective at preventing HIV from multiplying. Having less HIV in the body protects the immune system and prevents HIV from advancing to AIDS. ART also reduces the risk of HIV drug resistance.

ART can’t cure HIV, but HIV medicines help people with HIV live longer, healthier lives. HIV medicines also reduce the risk of HIV transmission (the spread of HIV to others).

What are the seven stages of the HIV life cycle?

The seven stages of the HIV life cycle are: 1) binding, 2) fusion, 3) reverse transcription, 4) integration, 5) replication, 6) assembly, and 7) budding. To understand each stage in the HIV life cycle, it helps to first imagine what HIV looks like.

HIV virus image

Now follow each stage in the HIV life cycle, as HIV attacks a CD4 cell and uses the machinery of the cell to multiply.

HIV Life Cycle Image

Where can I learn more about the HIV life cycle?

Visit this webpage from the National Institute of Allergy and Infectious Diseases (NIAID) to learn how HIV medicines work against the virus.