Epidemiologist Neil Ferguson created the highly-cited Imperial College London coronavirus model. The initial projection from Ferguson’s model projects 2.2 million dead people in the United States. It also projeImperialcts 500,000 dead in the U.K. from COVID-19.
That assumes no actions were taken to slow the virus and blunt its curve. The model predicts far fewer deaths if lockdown measures are undertaken. Organizations such as The New York Tines citations reference it and the study has been instrumental in governmental policy decision-making.
But one day after ordering lockdowns in the U.K., Ferguson is presenting revisions of the estimates. The author has drastic downgrades to the estimates. He is crediting lockdown measures. However, he is also revealing that far more people likely have the virus than his team figured.
The outcomes are revised. Should the actions remain the same?
Ferguson explained, “I should admit, we’ve always been sensitive in the analysis in the modeling to a variety of levels or values to those quantities. What we’ve been seeing, though, in Europe in the last week or two is a rate of growth of the epidemic which was faster than we expected from early data in China. And so we are revising our quotes, our central best estimate of the reproduction… something more, a little bit above of the order of three or a little bit above rather than about 2.5… the current values are still within the wide range of values which modeling groups [unintelligible] we should have been looking at previously.”
A higher rate of transmission than expected means more people have the virus than was previously expected. What this means is the mortality rate for the disease drops. This is true because the number of people with coronavirus is much higher so dividing by the same number of deaths results in a lower frequency of death, mortality rate.
Based on both those revised estimates and the lockdown measures taken by the British government, the epidemiologist predicts, hospitals will be just fine taking on COVID-19 patients and estimates 20,000 or far fewer people will die from the virus itself or from its agitation of other ailments, as reported by New Scientist Wednesday.
Ferguson’s change of tune comes days after Oxford epidemiologist Sunetra Gupta criticized the professor’s model. According to the Financial Times Gupta said, “I am surprised that there has been such unqualified acceptance of the Imperial model.” Professor Gupta led a team of researchers at Oxford in a modeling study which suggests that the virus has been invisibly spreading for at least a month earlier than suspected.
That led to the conclusion that as many as half of the people in the United Kingdom have already been infected by COVID-19. If her model is accurate, fewer than one in a thousand who’ve been infected with COVID-19 become sick enough to need hospitalization. This leaves the vast majority with mild cases or free of symptoms. Ferguson continues to argue that the Oxford model is too optimistic about death rates.
Amid widespread reporting on the new death-rate estimates, including by White House Coronavirus Response Coordinator Dr. Deborah Birx, Ferguson issued a statement on social media to “clear up confusion” about his revised estimates:
“I think it would be helpful if I cleared up some confusion that has emerged in recent days. Some have interpreted my evidence to a UK parliamentary committee as indicating we have substantially revised our assessments of the potential mortality impact of COVID-19. This is not the case.
Indeed, if anything, our latest estimates suggest that the virus is slightly more transmissible than we previously thought. Our lethality estimates remain unchanged. My evidence to Parliament referred to the deaths we assess might occur in the UK in the presence of the very intensive social distancing and other public health interventions now in place.
Without those controls, our assessment remains that the UK would see the scale of deaths reported in our study (namely, up to approximately 500 thousand).”