Antibody
\æntɪˌbɑdi\
A large, specialised / specialized Y-shaped protein produced by plasma cells (differentiated B cells) of the immune system to identify and neutralize foreign substances (antigens), such as bacteria, viruses, fungi, and toxins. These proteins, also known as immunoglobulins, bind specifically to antigens and help remove them from the body. Antibodies play a crucial role in the immune response by tagging antigens for destruction by other immune cells or neutralizing them directly. Each antibody has a unique structure that matches a particular antigen.
During the COVID-19 pandemic, serology tests were used to estimate how many people had developed antibodies to SARS-CoV-2, helping researchers better understand the true infection rate and distinguish the infection fatality rate (IFR) from the case fatality rate (CFR).
The purpose of vaccination is to train the immune system to recognize pathogens by exposing it to antigens – either through killed or weakened viruses, or via genetic instructions (as in mRNA vaccines) – so that it can produce antibodies and memory cells for future protection.