Have you ever asked yourself why people don’t usually get infected by the same disease twice in a short period? That’s because one of the amazing features of the immune system is its ability to remember past infections.
The first time a virus or bacterium invades the body, immune system cells called B cells and T cells recognize the specific molecules on the pathogen that are called antigens. At this initial stage, the body generates antibodies and mobilizes immune cells to combat the infection. Concurrently, some of these cells become long, lived memory cells.
Memory B and T cells live in the body for years, and sometimes even for decades. If the same pathogen manages to invade the body, they will identify it straight away and set off a vigorous and rapid immune response, producing a large quantity of antibodies within a few days as opposed to weeks.
This strong biological memory is also the basis for the effectiveness of vaccinesthey expose the immune system to the harmful pathogens so that it can respond to the real infection.
To put it simply, the immune system is like a sophisticated security system that keeps a record of past intruders and responds immediately when they come back.
If the immune system can remember infections for years, why do some diseases still infect us again and again?
MBH/PS