herd immunity
noun
: a reduction in the risk of infection with a specific communicable disease (such as measles or influenza) that occurs when a significant proportion of the population has become immune to infection (as because of previous exposure or vaccination) so that susceptible individuals are much less likely to come in contact with infected individuals
… when the percentage of people vaccinated against a particular disease drops, herd immunity begins to fail.—
Katherine Hobson
Katherine HobsonSerious streptococcal disease does seem to be on the rise, however, perhaps because invasive strains are circulating against which we have not had time to develop much "herd immunity," as epidemiologists say.—Wayne Biddle
Wayne BiddleExamples of herd immunity in a Sentence
Recent Examples on the Web
The numbers vary by school type — just 17% of charter schools have herd immunity, compared to 33% of private schools and 35% of public schools.
—Madeleine Parrish, The Arizona Republic, 30 July 2024
Research also shows that vaccines help build herd immunity and protect the body against disease.
—Solcyré Burga, TIME, 16 July 2024
That’s because the country has a good amount of herd immunity, either from vaccination, previous infections, or both.
—Michelle Marchante, Miami Herald, 11 July 2024
That herd immunity can protect people who can’t get vaccinated, such as those with weakened immune systems or serious allergies, by reducing their chances of infection.
—Tribune News Service, The Mercury News, 27 May 2024
See all Example Sentences for herd immunity 
Madeleine Parrish, The Arizona Republic, 30 July 2024
Research also shows that vaccines help build herd immunity and protect the body against disease.
—Solcyré Burga, TIME, 16 July 2024
That’s because the country has a good amount of herd immunity, either from vaccination, previous infections, or both.
—Michelle Marchante, Miami Herald, 11 July 2024
That herd immunity can protect people who can’t get vaccinated, such as those with weakened immune systems or serious allergies, by reducing their chances of infection.
—Tribune News Service, The Mercury News, 27 May 2024
See all Example Sentences for herd immunity
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'herd immunity.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
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Cite this Entry
“Herd immunity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/herd%20immunity. Accessed 20 Aug. 2024.
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herd immunity
noun
: a reduction in the probability of infection that is held to apply to susceptible members of a population in which a significant proportion of the individuals are immune because the chance of coming in contact with an infected individual is less
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