specific immunity

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specific immunity

physiology

Also known as: acquired immunity, adaptive immunity, specific, acquired immunity(Show More)

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July 14, 2026

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Specific immunity, also known as acquired or adaptive immunity, is the body's defense against infection that develops after exposure to a specific pathogen. Unlike innate immunity, which provides general protection from birth, acquired immunity is tailored to particular antigens. This protection is generated by specialized white blood cells called lymphocytes, specifically B cells and T cells.123

When the body encounters a pathogen, B cells produce antibodies that target and neutralize the invader (humoral immunity), while T cells directly attack infected cells (cell-mediated immunity). Crucially, some lymphocytes become memory cells, allowing for a faster and stronger response if the same pathogen is encountered again, providing long-lasting protection. This is why surviving certain diseases, like measles, often prevents reinfection.2415

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immune system
Specific, acquired immunity
It has been known for centuries that persons who contract certain diseases and survive generally do not catch those illnesses again. Greek historian Thucydides recorded that, when the plague was raging in Athens during the 5th century bce, the sick and dying…
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It has been known for centuries that persons who contract certain diseases and survive generally do not catch those illnesses again. Greek historian Thucydides recorded that, when the plague was raging in Athens during the 5th century bce, the sick and dying…
Read More

disease
Immunity
Specific immunity is acquired during the organism’s lifetime and involves the activation of white blood cells (B and T lymphocytes), which distinguish and react to foreign substances. B lymphocytes (or B cells) operate by producing antibodies, proteins that neutralize foreign molecules (
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Specific immunity is acquired during the organism’s lifetime and involves the activation of white blood cells (B and T lymphocytes), which distinguish and react to foreign substances. B lymphocytes (or B cells) operate by producing antibodies, proteins that neutralize foreign molecules (
Read More

blood
Lymphocytes
…regulate or participate in the acquired immunity to foreign cells and antigens. They are responsible for immunologic reactions to invading organisms, foreign cells such as those of a transplanted organ, and foreign proteins and other antigens not necessarily derived from living cells. The two classes of lymphocytes are not distinguished…
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…regulate or participate in the acquired immunity to foreign cells and antigens. They are responsible for immunologic reactions to invading organisms, foreign cells such as those of a transplanted organ, and foreign proteins and other antigens not necessarily derived from living cells. The two classes of lymphocytes are not distinguished…
Read More

immunity
Acquired immunity, by contrast, develops in response to exposure to a specific infectious agent or its products. It is stimulated by infection or vaccination and is characterized by the precise recognition of antigens (foreign substances) by B cells and T cells. When innate defenses are…
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Acquired immunity, by contrast, develops in response to exposure to a specific infectious agent or its products. It is stimulated by infection or vaccination and is characterized by the precise recognition of antigens (foreign substances) by B cells and T cells. When innate defenses are…
Read More