H3N2 vs H1N1: What’s the Difference Anyway? Kumar Jeetendra | March 18, 2023 The term “variant” is used to describe influenza viruses that have been detected in humans but are more commonly found in pigs. In July of 2011, influenza A H3N2 variant viruses were discovered in humans for the first time; these viruses are also known as “H3N2 viruses“ since they contain the matrix (M) gene originally …