Can we trust the Oxford study on Covid-19 infections? | Adam Kucharski

We don't know exactly how many people have already been infected with the virus, but there's no evidence it's half the population

" Adam Kucharski is an epidemiologist and author

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Earlier this month, the MSc students I teach at the London School of Hygiene & Tropical Medicine ran an outbreak investigation as part of their epidemiology assessment. They were told several people had fallen ill, and it was their job to piece together various fragments of information - about symptoms, timings and locations - to work out what might have happened.

We face the same challenge with every outbreak: we never have a single perfect dataset early on. Instead, we have to combine the information we do have to work out what might really be happening.