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How do antibodies help prevent reinfection by the same microorganism?

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Blood plasma — blood Blood sediment in test tubes, showing plasma (clear fluid), red blood cells (red), and the release of hemoglobin into the surrounding plasma (pink).

Antibodies help prevent reinfection through the mechanism of immunological memory, which allows the immune system to recognize and respond to a previously encountered microorganism much more rapidly and effectively.12

When an individual is first exposed to a pathogen, the immune system produces memory B cells alongside antibody-secreting plasma cells. These memory cells persist in the body for months or years. If the same microorganism enters the body again, these memory cells recognize the specific antigen and immediately divide to produce a new, large population of plasma cells. This triggers a rapid and powerful surge in the production of protective antibodies, which neutralize or destroy the pathogen before it can cause illness.3145

Once in the blood, these antibodies prevent infection by:
* Neutralization: Binding to toxins or surface molecules on microbes to prevent them from invading host cells.6
* Immobilization: Attaching to structures like flagella to stop movement.6
* Facilitating Destruction: Triggering the complement system to burst the microbe or attracting scavenger cells to ingest it.76