Focus – GS:III – Science and Technology
Context
A new study from Wuhan has studied the role of T-Cell Immunity against prolonged and sever COVID-19.
What are T-Cells?
- T cells are central players in the immune response to viral infection.
- For your immune system to fight off any kind of invader, such as a virus, you need a kind of white blood cell called a B cell, which makes antibodies, and a similar-looking white blood cell called a T cell.
- T cells can play different roles altogether.
- They can act as “killer cells”, attacking cells which have been infected with a virus or another kind of pathogen, or they can act as “helper cells” by supporting B cells to produce antibodies.
How do they function?
- Alongside antibodies, the immune system produces a battalion of T cells that can target viruses.
- Some of these, known as killer T cells (or CD8+ T cells), seek out and destroy cells that are infected with the virus.
- Others, called helper T cells (or CD4+ T cells) are important for various immune functions, including stimulating the production of antibodies and killer T cells.
- T cells do not prevent infection, because they kick into action only after a virus has infiltrated the body. But they are important for clearing an infection that has already started.
- In the case of COVID-19, killer T cells could mean the difference between a mild infection and a severe one that requires hospital treatment.
What did the latest research find?
- neutralising antibodies were detectable even 12 months after infection in “most individuals”.
- “multifunctional T cell responses were detected for all SARS-CoV-2 viral proteins tested”.
- the magnitude of T cell responses did not show any difference immaterial of how severe the disease was.
- While the ability of antibodies to neutralise was nearly absent against the Beta variant, it was reduced in the case of the Delta variant.
Source – The Hindu
