IE 10 or 11 may display this page improperly. Please upgrade to Microsoft Edge, Google Chrome, or Firefox.

What are Influenza Type A Flu and Type B Flu?

600x300 200214561.jpg?h=300&la=en-US&w=600&v=1-201704070723

What are Influenza Type A Flu and Type B Flu?


When it comes to the flu, not all types are created equal. You’ve probably heard that there are a few different types of the flu. According to the CDC, there are three types of influenza viruses: influenza A, influenza B and influenza C. Influenza A and B are the two main types that routinely spread in humans and cause seasonal flu epidemics. Influenza C viruses cause only mild respiratory infections and are not thought to be responsible for epidemics. 

Influenza A viruses are the most harmful, as they can cause severe disease. Wild aquatic birds are often the hosts for a large variety of influenza A viruses. Sometimes these viruses are transmitted from bird to human and can cause devastating outbreaks. Some of the subtypes of influenza A that have caused the largest number of known human deaths are:

  • H1N1, which caused Spanish Flu in 1918 and Swine Flu in 2009

  • H2N2, which caused Asian Flu in 1957

  • H3N2, which caused Hong Kong Flu in 1968

  • H5N1, which caused Bird Flu in 2004

Influenza B almost exclusively infects humans and is less common than influenza A. Flu type B also mutates about two to three times more slowly than influenza A. Because humans are the natural host of influenza B, pandemics generally do not occur with influenza B viruses. Although scientists can classify and monitor the different types of flu viruses, it is virtually impossible for them to develop effective vaccines that provide lifelong immunity. The reason: Flu viruses mutate (change their genetic structure) and replicate (produce new, identical copies of themselves) extremely quickly, making it difficult for scientists to keep up.

The good news is most people will recover from the flu on their own. However, if you have a severe case of the flu, you should see your healthcare provider. Not sure if you have the flu? A good indication of whether or not you have the flu is if a  indicates you have a fever.

While over-the-counter medications cannot cure the flu, they can help ease your symptoms while you wait for it to run its course. If you’re suffering from a sore throat, headache, cough, fever, or minor aches and pains, NyQuil Cold & Flu and DayQuil Cold & Flu are both good options since they contain a pain reliever/fever reducer and cough suppressant. NyQuil Cold & Flu also relieves runny nose and DayQuil Cold & Flu also relieves nasal congestion. If you’re suffering from more symptoms, try NyQuil COMPLETE Cold & Flu, which also contains a nasal decongestant, and DayQuil COMPLETE Cold & Flu, which has an expectorant to help loosen phlegm and thin bronchial secretions to rid the bronchial passageways of bothersome mucus. Soon enough, you’ll be on the road to recovery.

View Sources



by product

      by symptom

        help & support

        • Contact Us
        • For ingredients and more, Select a product