People can contract influenza, an infectious respiratory illness. Fever, sore throat, runny nose, cough, headache, aches in the muscles, and fatigue are among the symptoms. In severe cases, pneumonia frequently results in death. There are worldwide influenza pandemic outbreaks, despite the fact that these illnesses are marked by sporadic seasonal epidemics and irregular and unpredictable occurrences. a zoonotic viral strain. Severe influenza seasons are linked to the H3N2 subtype. Three of the previous five extremely severe influenza seasons were dominated by H3N2 viruses. influenza viruses are evolving so quickly, even with known techniques, The best ways to avoid and cure influenza is viewed as a tremendous task. Only thorough research on the currently dominating H3N2 influenza viruses will lead to improvements in vaccination efficacy and pandemic risk assessment. The different characteristics of the H3N2 viruses and their ability to cause seasonal outbreaks and pandemics are covered in great length in this article.