-
- To save this word, you'll need to log in.
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
Serious 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
Examples of herd immunity in a Sentence
Recent Examples on the Web
The declaration called for speeding herd immunity by allowing people at low risk to get infected while protecting those most vulnerable, like the elderly.
—Rob Stein, NPR, 26 Nov. 2024
China would need to vaccinate 70 to 80 percent of its population in order to meet the requirements of herd immunity.
—Yanzhong Huang, Foreign Affairs, 11 Mar. 2021
In 2020, then NIH director Francis Collins and other public health officials rejected the Great Barrington Declaration, an open letter which Bhattacharya co-authored that argued against lockdowns and promoted herd immunity during the coronavirus pandemic.
—Yaakov Katz, Newsweek, 28 Nov. 2024
His nominee for secretary of Defense, Pete Hegseth, pushed for herd immunity in May 2020 and encouraged anti-lockdown protests.
—Benjamin Mazer, The Atlantic, 25 Nov. 2024
See all Example Sentences for herd immunity
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Word History
First Known Use
1917, in the meaning defined above
Articles Related to herd immunity
Dictionary Entries Near herd immunity
Cite this Entry
“Herd immunity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/herd%20immunity. Accessed 23 Dec. 2024.
Kids Definition
herd immunity
noun
: a reduction in the risk of catching a disease (as measles) that occurs when enough people have become immune to infection (as through previous exposure or vaccination) that susceptible people are far less likely to come in contact with infected people
Medical Definition
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
Love words? Need even more definitions?
Merriam-Webster unabridged
Share