H1N1

American

Pathology.

a subtype of the type A influenza virus, with strains that give rise to seasonal epidemics, or sometimes pandemics, including a strain with swine, avian, and human genes responsible for swine flu.

Etymology

Origin of H1N1

First recorded in 1970–75; abbreviation of h(aemagglutinin type)1 and n(euraminidase type) 1

Example Sentences

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H1N1

Public health scientists at the Columbia University Mailman School of Public Health used advanced computer simulations to trace how the 2009 H1N1 flu pandemic and the 2020 COVID-19 pandemic spread across the United States.

From Science Daily ● Feb. 7, 2026

There are also signs a different strain of flu - H1N1 - is picking up in Europe and may lead to an increase in cases here too.

From BBC ● Dec. 19, 2025

The 1918 influenza pandemic is thought to have been caused by a reassorted combination of an H1N1 bird flu with a more common flu.

From Slate ● Dec. 4, 2024

It happened again in 2009, when a human and swine flu switched genes, unleashing the H1N1 swine flu outbreak that killed roughly 500,000 people.

From Los Angeles Times ● Nov. 26, 2024

In early 2024, Peiris and his colleagues published a study suggesting that previous infection with the H1N1 swine flu may provide some protection against H5N1.

From Salon ● Jul. 23, 2024

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023