Question: why are eggs used to help create some vaccines?

James Beswick answered on 21 May 2020:

Great question – I never realised this! I’ve done a bit of research and it turns out that in vaccine development, the virus is grown in the yolk of fertilised eggs. Viruses are a bit rude, they can’t reproduce on their own – so they infect a cell and take it over, forcing the host cell to make new viruses. So scientists use eggs as a sort of ‘virus factory’ to allow the virus to replicate, then scientists can isolate the virus for their research. Here’s a website from the US FDA with more information: https://www.fda.gov/consumers/consumer-updates/fdas-critical-role-ensuring-supply-influenza-vaccine