Sep 26, 2025 · There are four types of influenza viruses: A, B, C, and D. Influenza A and B viruses cause seasonal epidemics of disease in people (known as flu season) almost every winter in the …

Influenza viruses comprise four species, each the sole member of its own genus.

Dec 18, 2025 · Influenza A is the most common and most dangerous type of flu virus in humans. It is responsible for nearly all seasonal flu epidemics and every known flu pandemic. What sets Influenza …

Jan 23, 2025 · Three types of flu viruses affect humans: types A, B, and C. Type A and B cause the annual influenza epidemics that have up to 20% of the population sniffling, aching, coughing, and …

Feb 28, 2025 · There are 4 types of influenza viruses, types A, B, C and D. Influenza A and B viruses circulate and cause seasonal epidemics of disease. Influenza A viruses are further classified into …

Nov 21, 2025 · Key takeaways: There are four main strains or types of influenza virus: A, B, C, and D. Influenza A and B viruses cause the flu season each year. Flu virus strains are always changing. …

Sep 26, 2023 · There are three types of flu viruses that affect people. They’re known as influenza viruses A, B and C. Influenza A and influenza B viruses are the heavy hitters. They’re the ones that …

This topic portal, hosted by the Centers for Disease Control and Prevention (CDC), provides an overview of the different types of influenza viruses, including influenza A, B, C, and D.

There are four types of influenza viruses: influenza A, influenza B, influenza C, and influenza D. The A and B viruses cause seasonal epidemics in humans—commonly referred to as “flu season”—which …

While there are technically 4 types of flu, there are also different subtypes. To start, let’s go over the four different types of flu viruses – A, B, C, and D: