Posts Tagged “antigenic drift”

Did you ever think about only one disease that causes the death of 50 million people? and around a year!!!!

Unfortunately, it already happened between 1918-1919 and is known as Spanish flu.

Flu (influenza) is a highly contagious respiratory infection caused by influenza viruses, which are divided into three types A, B and C.

Type A influenza is the most frightening and epidemic.

Type B influenza  causes milder symptoms than type A.

Type C influenza tends to be mild and does not spark epidemics.

Type A flu virus is subdivided into subtypes based on two surface proteins, hemagglutinin (HA) and  neuraminidase (NA).

Now, Scientists know 16 HA subtypes and 9 NA subtypes of the flu virus.

A (H1N1) and A (H3N2) are the  subtypes of influenza A viruses found in people, and there are no subtypes of influenza B virus.


The influenza viruses contain eight segments of single-strand RNA ,  continually change over time through “antigenic drift” or “antigenic shift”.

So, there is new flu vaccine every year and from time to time we face a new flu outbreaks.

Now, there is real fear between scientists and people of transmission of influenza viruses from animals to people.

There is a promising trial of new flu vaccine , targeting the internal proteins of the virus, this vaccine may be used in vaccination of many viruses like flu in mechanism of infection. (you can see BBC report Here).

References :


What Is Flu?

Types of flu

Influenza virus

History of Flu Epidemics

The Influenza (Flu) Viruses

Types of Influenza Viruses

Flu Virus Can Change: “Drift” and “Shift”

For Further reading

Seasonal Flu

Flu Channel

Cold Channel

Bacterial Pneumonia and 1918 flu

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