Exercise Cygnus was a simulation exercise carried out by NHS England in October 2016 to estimate the impact of a hypothetical H2N2 influenza pandemic on the United Kingdom.[1][2][3] The exercise showed that the pandemic would cause the country's health system to collapse from a lack of resources,[2][4] with Sally Davies, the Chief Medical Officer at the time, stating that a lack of medical ventilators and the logistics of disposal of dead bodies were serious problems.[5][6] As of April 2020[update], the full results of the exercise remained classified.[7]
The Daily Telegraph reported one government source as saying that the results of the simulation were "too terrifying" to be revealed.[2] According to the Telegraph, the exercise led to assumptions that a "herd immunity" approach would be the best response to a similar epidemic.[8][9]
A number of news reports criticised the government's handling of the COVID-19 pandemic in the light of the conclusions reached by Exercise Cygnus.[2][4]
In late April 2020, The Observer reported that the government had been threatened with legal action over demands to publish the results of the study.[10] The report, classified as "Official - Sensitive", was leaked and published in full in The Observer's sister paper The Guardian (except for redaction of some contact details) on 7 May 2020.[11][3]