Types of flu

There are three types of flu viruses: A, B, and C. Type A and B cause annual influenza epidemics that can lead to 20% of the population sniffling, aching, coughing, and running high fevers. Type C also causes flu; however, type C flu symptoms are much less severe.

Type A

The Type A flu virus is constantly changing and is generally responsible for large flu epidemics. There is also an A2 virus which is spread by people who are already infected. Type A flu viruses are also capable of infecting animals and wild birds commonly act as hosts for this flu virus.

Type B

Unlike type A flu viruses, type B flu is found only in humans. Type B flu may cause a less severe reaction than type A flu virus, but occasionally can still be extremely harmful. Influenza type B viruses do not cause pandemics.

Type C

Influenza C viruses are also found in people. They are, however, milder than either type A or B. People generally do not become very ill from the influenza type C viruses and they do not cause epidemics.

Different strains of the flu virus mutate over time and replace the older strains. This is why it is important to have a flu jab each year to ensure that your body develops immunity to the most recent strains of the virus.

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Information about Influvac® Tetra (Influenza Vaccine/Surface Antigen/Inactivated) can be found in the patient information leaflet.

INF-2021-0178 DOP: September 2022

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