HIV, or Human Immunodeficiency Virus, is a virus that attacks the immune system, weakening it and making it harder for the body to fight off infections and diseases.

HIV targets CD4 cells, a type of white blood cells that are essential in helping the body defend itself against infections. As HIV progresses, it can lead to Acquired Immunodeficiency Syndrome (AIDS), a condition where the immune system is severely compromised, putting the individual at an increased risk of infections and cancers.

How HIV is Transmitted

There are several ways HIV can be transmitted, including:.

Unprotected sexual contact with an infected individual
Sharing needles/syringes with an infected individual
Blood transfusion from an infected individual (rare in developed countries)
Vertical transmission (mother-to-child during pregnancy, childbirth, or breastfeeding)

Why Do Some People Remain Immune to HIV?

Despite the widespread nature of HIV, there are individuals who are resistant or immune to the virus despite being exposed to it. Scientists have identified three types of individuals who are resistant to HIV:.

1. The CCR5 Mutations

The CCR5 mutations are individuals who have a genetic mutation that affects the CCR5 receptor, a protein found on the surface of cells that HIV uses to enter the CD4 cells.

The CCR5 mutation stops HIV from being able to enter the CD4 cells, making the individual resistant to the virus. Studies have shown that around 1% of people of European descent have this genetic mutation, making them immune to HIV. The CCR5 mutation is not as common in other populations and is found in less than 0.1% of people of African or Asian descent.

2. Elite Controllers

Elite controllers are individuals who have been infected with HIV but have never progressed to AIDS. These individuals have an incredibly strong immune system that can effectively fight off the virus and keep it at low levels in their body.

Studies have shown that around 1-5% of HIV-positive individuals are elite controllers.

3. Non-Progressors

Non-progressors are individuals who have been infected with HIV but have not progressed to AIDS, despite not having the same level of resistance as elite controllers.

These individuals have a slow-progressing form of the virus and may not need antiretroviral therapy to manage their infection. Non-progressors make up around 5-15% of HIV-positive individuals.

Current Research on Immunity to HIV

Understanding why some individuals are immune to HIV is important in developing new treatments and therapies for those living with the virus.

Researchers are continuing to study the immune systems of elite controllers and non-progressors to understand what it is about their immune system that is so effective at controlling the virus. The CCR5 mutation has also been the focus of research, with scientists attempting to use gene editing to create the mutation in individuals without it.

Preventing HIV Transmission

While there are individuals who are immune or resistant to HIV, the best way to prevent transmission is through education and prevention efforts. This includes:.