1. 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.

Origin of H1N1

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

Words Nearby H1N1

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use H1N1 in a sentence