Nov 03, 2024

What is HIV?

Article on how HIV works and its dangers

Welcome to this article dedicated to HIV (Human Immunodeficiency Virus) and its impact on the immune system. You will discover how this virus works, the consequences for the body, and the means of prevention and treatment. Before you begin, test your knowledge with this quick quiz.

Test your knowledge of the HIV virus

What is HIV?

HIV is a virus that attacks the immune system, specifically CD4+ T cells, which play a key role in the body's defense against infections. By weakening these cells, HIV makes the body more vulnerable to a multitude of opportunistic infections and diseases.

Did you know? Unlike other viruses, HIV cannot be eliminated by the immune system alone. Without treatment, HIV can progress to AIDS (Acquired Immunodeficiency Syndrome), a stage where the immune system is severely damaged.

Figure 1: Image of an HIV virus attacking a T cell. Credit: NIH/NIAID

Why is HIV so dangerous?

HIV is particularly dangerous because it attacks essential cells in our immune system. By destroying CD4+ T cells, the virus weakens the body's ability to fight minor infections that would be harmless in a healthy body. It is this progressive reduction in immune defenses that allows infections or cancers that are normally mild to become potentially fatal.

With antiretroviral (ARV) treatment, HIV can be controlled, and people who are infected can live long lives with a good quality of life. These treatments stop the virus from multiplying, reducing its viral load in the blood to undetectable levels.

Figure 2: HIV-1 virus forming on an infected cell. This image shows HIV-1 virus particles (red/yellow) forming and replicating from an infected H9 cell (blue/green). Credit: NIAID.

How does HIV infect cells?

Once in the body, HIV targets CD4+ T cells by attaching to their surface via a protein called gp120. The virus then enters the cell and releases its genetic material. Using an enzyme called reverse transcriptase, HIV converts its RNA into DNA, which it then integrates into the genome of the infected cell. The host cell then begins to produce new HIV viruses, which spread throughout the body and infect other cells.

Did you know? Although HIV can remain dormant for years, it continues to progressively destroy CD4+ T cells, compromising the immune response.

What do you think?

Is there any promising research on an HIV vaccine?

Expert's answer: According to a US study, this vaccine currently being tested on monkeys has reduced their risk of HIV infection by 79%: an extremely encouraging result. Indeed, "despite nearly four decades of efforts by the global scientific community, an effective vaccine against HIV [remained until now] an elusive goal," according to Dr. Anthony Fauci, co-author of the study and White House adviser on the Covid-19 health crisis. So, the correct answer is "Yes."