A mother, who had suffered from chickenpox in her childhood, is now taking care of her child, who is suffering from the same disease. What are the chances of the mother having chickenpox? Explain.
The chances of mother having chickenpox are nil because she became immune to this disease. When the immune system first encounters an infectious microbe, it responds against it and then remembers it specifically.
So, when the next time that particular microbe enters into the body, the immune system responds with greater vigour and eliminates infection more quickly. Thus, eliminating any chance of further infection.