acquired immunity

American  

noun

Immunology.

1. immunity arising from exposure to antigens.

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acquired immunity British  

noun

1. the immunity produced by exposure of an organism to antigens, which stimulates the production of antibodies

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acquired immunity Scientific  

1. Immunity that is not inherited. Acquired immunity can be active or passive.

2. ◆ Active immunity results from the development of antibodies in response to an antigen, as from exposure to an infectious disease or through vaccination.

3. ◆ Passive immunity results from the transmission of antibodies, as from mother to fetus through the placenta or by the injection of antiserum.

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Etymology

Origin of acquired immunity

First recorded in 1930–35

Example Sentences

Thankfully, deaths have declined sharply from their peak during the Omicron surge, thanks to vaccination and acquired immunity from previous infections, which can make it feel like the virus is in the rearview.

From Salon • Mar. 14, 2025

These broadly reactive antibodies likely represent a common mechanism of acquired immunity to severe malaria and offer novel insights for the design of a PfEMP1-based vaccine or treatment targeting severe malaria.

From Science Daily • Nov. 20, 2024

Fortunately, the current Omicron variant appears to be less virulent than the Delta variant, which surfaced in the summer of 2021, and more people have acquired immunity to the coronavirus by now.

From New York Times • Mar. 16, 2023

Still, the combination of acquired immunity through prior infection and vaccination — plus the refined boosters — have Mr. Biden hoping for a better winter this time.

From Washington Times • Oct. 25, 2022

As soon as the animals' period of acquired immunity is over and favorable conditions present themselves, the contagion breaks out with renewed virulence.

From Special Report on Diseases of Cattle by United States. Bureau of Animal Industry