Dictionary.com
definitions

active immunity

noun Immunology.

immunity in an organism resulting from its own production of antibody or lymphocytes.
Compare passive immunity.

Origin of active immunity

First recorded in 1910–15
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
active immunity in Medicine

active immunity

n.

Immunity resulting from the development of antibodies in response to the presence of an antigen, as from vaccination or exposure to an infectious disease.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
active immunity in Science

active immunity

See under acquired immunity.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.