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How are seasonal flu vaccines made? © Getty Images

How are seasonal flu vaccines made?

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Every January, government organisations and health researchers meet to decide which strains of influenza virus present the biggest threat for the following winter.

Asked by: Robert Leslie, Poole

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Every January, government organisations and health researchers meet to decide which strains of influenza virus present the biggest threat for the following winter. The three or four worst strains are then injected into fertilised chickens’ eggs and incubated so that the virus will multiply.

After a few days the egg white protein containing virus particles is extracted and chemically inactivated, so it can’t cause flu itself. The vaccine is a dilute solution of this mixture, with some preservatives added.

Last year a new technique became available, which inserts DNA sequences into bacteria so that they will produce virus proteins. This has the same effect as stimulating your immune system but it’s much faster to manufacture.


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Authors

luis villazon
Luis VillazonQ&A expert

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.

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