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?
Nice article. I came to know first time about our immune system and the memory cells remember the virus for years. The image explains well. Chosen a wonderfull topic.
I apprecaite the author for writing this wonderful piece of informtion.
Thank you so much for your kind words. I’m really glad you found the topic interesting and that the explanation and image helped in understanding how immune memory works.
This post made me amazed about how many wonders does human body enfolds within. Our immune system keeps on fighting for us continuosly without any efforts from our side. However, some diseases still infect us again and again even though immune system can remember infections for years, this is because the pathogens undergo changes in their antigens to escape the immune system. The term for this is “Antigenic Variation”.
Yes, our immune system recognises the pathogen infected in past in our body but it still infects us maybe because the pathogen changes it’s structure, mutate over time hence the immune system cannot recognise it quickly.
Well said. The human immune system is truly fascinating. And yes, antigenic variation is a key reason why some infections keep recurring despite immune memory pathogens keep changing to escape our defenses.
Exactly. Even though the immune system remembers past infections, pathogens can mutate and change their structure, making it harder to recognize them quickly leading to reinfections.
