CBSE Class 9 Answered

Children in many parts of India get immune to Hepatitis 'A' by the time they are 5 years old because they are exposed to this disease through polluted water. Therefore, in their early childhood, majority of the children get exposed to Hepatitis A virus which can spread through contaminated water. During childhood, the effect of the disease is mild and the child’s body produces antibodies against the virus which provides them immunity. As a result, these children do not need vaccination and they become resistant to the disease permanently.