Prof Wood said: “It does seem possible that the social distancing that was happening before full lockdown might have done the trick.
“My results simply suggest that if you do not make strong assumptions about what happened, then the data tend to suggest a peak a few days before lockdown.”
He said it was difficult to be completely sure when infections peaked in Britain because community testing was stopped in mid-March so there was no data from early in the epidemic.
However his analysis also showed that Sweden’s infections peaked just a few days after Britain, even without full lockdown being imposed in that country. The German reproduction ‘R’ number was also estimated to have fallen below one before full lockdown.
In the work, published on the open access research site arXiv, hosted by Cornell University, Prof Wood said the results had ethical implications for keeping lockdown in place or reinstating it later in the year because it could have disastrous long term implications on the nation’s health.
“These facts have implications for the policies to be adopted in the coming autumn, particularly given the peculiar ethical issues associated with lockdown,” he said. “For example, plausible estimates of the life loss burden from an unmitigated Covid-19 epidemic in the UK are about two weeks per person.
“A plausible lower bound on the UK life loss from the 2008 financial crisis and its aftermath is seven weeks per person. The economic shock from lockdown is substantially larger than 2008.”