The ability to respond to microbes after birth is called acquired immunity. Acquired immunity is a specific immunity. It is of two types.
Active defense and passive defense
- Active Immunity: The defense achieved through the production of antibodies in the body is called active immunity. Active defense is of two types. These are-
(i) Natural Active Defense: Infection occurs when humans are involuntarily exposed to microbes. All these germs are eradicated by naturally acquired abilities.
(ii) Artificial active immunity: Humans acquire this immunity through inoculation or vaccine. For example, DDP vaccine is taken for diphtheria, tetanus vaccine for scurvy and pertussis vaccine for whooping cough.
- Passive Immunity: The immunity acquired by the transfer of antibodies from one body to another is called passive immunity. Passive defense is of two types. These are-
(i). Natural Passive Defence: Antibodies come from the mother’s body to the baby through colostrum and colostrum. It makes children immune to disease.
(ii). Artificial passive immunity: The body is made immune to disease by transferring antibodies from one body to another through injection.