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## Table 17.1: Differences between active and passive immunity | Active Immunity | Passive Immunity | |---|---| | 1. Produced by one's own body | 1. Received from outside, i.e. not developed by one's own body. | | 2. Induced by infection or by contact with immunogens (immunity-producing agents such...

## Table 17.1: Differences between active and passive immunity | Active Immunity | Passive Immunity | |---|---| | 1. Produced by one's own body | 1. Received from outside, i.e. not developed by one's own body. | | 2. Induced by infection or by contact with immunogens (immunity-producing agents such as vaccines, allergens, etc.) | 2. Provided by ready-made antibodies. | | 3. Provides effective and long-lasting protection. | 3. Protection is less effective and temporary i.e. it does not ensure protection against a subsequent infection. | | 4. Immunity effective only after a certain time gap (time required for production of antibodies). | 4. Immediately effective. | | 6. Some antibodies are present in the blood of some people from the very birth. Such people having these particular antibodies in their blood do not suffer from those particular diseases even if the germs for them have crossed the barriers and escaped the phagocytes. | 7. Immunity produced by the antibodies on exposure to antigens may be either for a short period (as in common cold, cholera) or for a longer period (as in small pox, measles, etc.) | ## Summary of our body's defence against disease - causing germs **A. Barriers (Prevent entry of germs)** * **A1. Prevent entry mechanically** * Tough outermost layer of skin * Blood clot plug at any cut * **A2. Prevent entry by killing** * Hairs on skin and in nose * Cilia in wind pipe