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. 14, 15
Influenza A vs B: Brief History & Transmission
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:14, 15
- H1N1, which caused Spanish Flu in 1918 and Swine Flu in 20091
- H2N2, which caused Asian Flu in 19572
- H3N2, which caused Hong Kong Flu in 19683
- H5N1, which caused Bird Flu in 20044
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.22
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.22
Signs of Influenza A or Influenza B Symptoms
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 thermometer indicates you have a fever.
Influenza A and Influenza B Treatment
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, runny nose, 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. If you’re suffering from more symptoms, try NyQuil SEVERE Cold & Flu, which also contains a decongestant, and DayQuil SEVERE Cold & Flu, which has an expectorant to help loosen congestion in your chest. Soon enough, you’ll be on the road to recovery.