When our body encounters a pathogen for the first time, the immune response is generally low but on exposure to the same pathogen again, the immune response by the body is much more compared to the first exposure. Why is it so?
When the body encounters a pathogen for the first time, the immune system takes time to recognise the pathogen and develop a response.
During this primary response, the body produces specific antibodies and creates memory cells that remember the pathogen.
On subsequent exposure to the same pathogen, these memory cells quickly recognise it and trigger a faster, stronger, and more effective immune response.
This is the principle behind vaccination, where vaccines train the immune system using weakened or harmless parts of a germ to create memory cells for future protection.
Explanation
The chapter explains that vaccines help our body fight certain diseases by training the immune system to recognise and attack harmful germs, providing acquired immunity. A vaccine contains weakened, dead, or harmless parts of a pathogen that helps the immune system develop protection without causing the disease. The immune system creates memory cells during this process.
Solution Steps
During first exposure, the immune system takes time to recognise the pathogen and develop a response
The primary response produces specific antibodies and creates memory cells that remember the pathogen
On subsequent exposure, memory cells quickly recognise the pathogen and trigger a faster, stronger immune response
Vaccination uses this principle by training the immune system with weakened or harmless parts of a germ