The New Highly Virulent HIV Strain
Published in
3 min readFeb 13, 2022
The VB variant is more severe and transmissable, is this a step backwords in HIV research?
What is it?
- HIV (human immunodeficiency virus) is a virus that damages the cells in your immune system and weakens your ability to fight everyday infections and disease.
- Sufferers that do not receive treatment can end up completely immunocompromised (acquired immunodeficiency syndrome, AIDS)and much more susceptible to common infections which, without a reliable immune system, can become fatal.
- Researchers have identified a new strain of HIV, the VB variant, that has been circulating in the Netherlands for the past decade.
- It’s more transmissable and severe than other strains.
- Whilst viruses tend to generally evolve to become less virulent over time and thus more successful, infecting a greater proportion of people with lower mortality, this new strain does not seem to follow this trend.
What’s different?
- The VB variant boosts the number of viral particles in a person’s blood, making them more likely to transmit the virus.
- It also seems to lead to a reduction in immune cells called CD4 T cells, so infected people are at risk of developing AIDS much more rapidly than those with other versions of HIV.
- Compared with people infected with other HIV strains, those infected with the new variant had up to 5.5 times more virus in their blood, and their CD4 T cell levels dropped nearly twice as fast, placing them at risk of developing AIDS much more rapidly.
- A drop in CD4 T cells, which help to coordinate the body’s immune response to infections, is a tell-tale sign that HIV has damaged the immune system.
- Researchers estimate that, without treatment, people infected with this variant would develop AIDS within 2–3 years after diagnosis, compared with 6–7 years for those infected with other HIV strains.
- Individuals with the VB variant also showed an increased risk of transmitting the virus to others.
How do we treat it?
- Luckily, the VB variant is susceptible to antiretorviral drugs and current HIV treatment.
- After starting treatment, individuals with the VB variant had similar immune system recovery and survival to individuals with other HIV variants.
- However, the researchers stress that because the VB variant causes a more rapid decline in immune system strength, this makes it critical that individuals are diagnosed early and start treatment as soon as possible.
- Research into the new VB strain and the mechanisms in which it achieves its higher virulence and transmissibility could reveal new targets for next-generation antiretroviral drugs, so the future still looks bright for HIV therapy!
References:
Wymant, C. et al. Science 375, 540–545 (2022).
