Answers to Common Cold and Flu Questions

Premier Health providers answer frequently asked questions about cold and flu.

What is the difference between influenza A, B, and C?

Influenza – commonly known as the flu – is classified as three different types based on its nucleic acids and protein composition, according to the National Institutes of HealthOff Site Icon (NIH).

Once tested, the flu is categorized as Type A, Type B, or Type C.

Type A flu viruses are found in humans and also in some animals, including ducks, chickens, and pigs, according to the NIH.

There are numerous types and subtypes of the Type A flu virus. Type A usually has the most severe flu symptoms and most frequently leads to extreme illness, including hospitalization and even death, according to the Centers for Disease Control and PreventionOff Site Icon (CDC).

Type B flu viruses are common among humans, according to the NIH.

The symptoms of Type B are similar to Type A. Both influenza A and B are immunized against in the annual flu vaccine, according to the CDC.

Influenza Type C has much milder symptoms, according to the NIH. It causes mild respiratory infections, but it is not severe enough to cause global outbreaks like Type A has in the past.

Symptoms of Type C are most similar to those of a cold, and the flu vaccine does not protect against influenza Type C viruses, according to the CDC.

For more about the difference between influenza types A, B, and C, talk with your doctor.

Learn more:

Source: Meghan Brewster, MD, Beavercreek Family Medicine; Christopher Lauricella, MD, Family Medicine of Vandalia; Sally McIntyre, MD, Belmont Physicians; Josh Ordway, MD, Franklin Family Practice; Guillermo Trevino, MD, Covington Family Care; Lauren Roth, MD, Phillipsburg Family Care; Susan Davis-Brown, MD, Brookville Family Care; Amanda Fox, CNP, Dulan and Moore Dulan Family Wellness Center; Angelia Mickle, DNP, Jamestown Family Medicine; Leelmohan Ravikumar, MD, Troy Primary Care Physicians; Janet Smith, CNP, Southtown Family Practice; Aaron Block, MD, MPH, Franklin Family Practice; Anoopa Hodges, DO, Oakwood Primary Care

Sally S. McIntyre, MD

Sally S. McIntyre, MD

Belmont Physicians

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Guillermo "Bill" Trevino, MD

Guillermo "Bill" Trevino, MD

Miami County Internal Medicine

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