Q- A person who has already suffered from chickenpox has less chances of catching it again why?
Answer- It is absolutely right that a person who already suffered from disease such as chickenpox do not become victim again of that same disease in other words there are very little chances of catching it again because our body (human body) has a proper immune system that stores the genetic structure or data of the virus or bacteria that causes disease.
For an example if any person suffered from smallpox so his or her body stores the data of in form of blueprint of the DNA of that bacteria or virus causing small pox. So when ever that bacteria or virus enter in body so they easily determine its DNA structure and can easily produce antibodies against it.
In this way our body defense against viruses and bacteria that enter inside our body. This is the reason behind why person has less chance of catching chickenpox against if previously he or she had suffered from that disease.