| Active Immunity | Passive Immunity |
| 1. It is produced due to contact with pathogen or its antigen. | 1. It is produced due to antibodies obtained from outside. |
| 2. Immunity is not immediate. A time lapse occurs for its development. | 2. Immunity develops immediately. |
| 3. It lasts for sufficiently long **, may be life long. | 3. It lasts for a few days. |
| 4. Antibodies are produced by the body in response to pathogen or antigen. | 4. Antibodies are obtained from outside. |
| 5. Side effects are very few. | 5. At times the body reacts to the introduction of antisera. It is called serum sickness. |
