After recovery from the primary infection, resistance to the organism ismediated by cellular immunity (by CD4-positive T cells and macrophages)

After an individual recovers from a primary infection, their body develops a resistance to the organism that caused the infection. This resistance is mediated by cellular immunity, which involves the action of CD4-positive T cells and macrophages.

Here's a step-by-step breakdown:

1. Primary Infection: This is the first time an individual is infected by a specific organism. The body's immune system responds to this infection, and eventually overcomes it.

2. Recovery: After the immune system has successfully fought off the infection, the individual recovers. During this recovery period, the body begins to develop a resistance to the organism that caused the infection.

3. Resistance: This resistance means that if the individual is exposed to the same organism again, their immune system will be able to respond more quickly and effectively, preventing or reducing the severity of a secondary infection.

4. Cellular Immunity: This resistance is mediated by a specific part of the immune system known as cellular immunity. This involves the action of CD4-positive T cells and macrophages.

5. CD4-positive T cells: These are a type of white blood cell that play a key role in the immune system. They help to coordinate the immune response by signaling other cells in the immune system to perform their specific functions.

6. Macrophages: These are another type of white blood cell that are involved in detecting, engulfing and destroying pathogens and apoptotic cells.

So, in summary, after recovery from a primary infection, the body develops a resistance to the organism that is mediated by the action of CD4-positive T cells and macrophages, which are key components of the cellular immune system.