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Why do we need a new flu jab every year?

Intro

In 1933 scientists at the National Institute for Medical Research discovered the virus that causes flu. Four years later they realised flu viruses aren’t all the same.

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Why do we need a new flu jab every year?

Because viruses can only reproduce in living things, researchers grew flu in hen’s eggs during early vaccine trials. Their studies in the 1930s and 1940s suggested each annual/seasonal flu outbreak was caused by a different strain of the virus.

To keep pace, the Worldwide Influenza Centre opened in 1948. Researching, collecting and sharing information about active strains, the Centre enabled vaccine manufacturers to target jabs against the right strain every year.

Black and white photo of flu researchers

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Today

Today

The Worldwide Influenza Centre is part of a global surveillance system coordinated by the World Health Organization and still plays a critical role in updating the annual flu vaccine.

The centre moved to the Crick in 2015. Its researchers study changes in the structure of active flu strains and how the vaccine can help our immune system to recognise and tackle these.

The knowledge gained from this work has helped our researchers advance understanding of COVID-19 variants.

John McCauley

John McCauley, Director of the Worldwide Influenza Centre