There is so much coronavirus research being published that has a bearing on the important public policy issues of what mitigation measures are appropriate that it is hard to keep up with it all. Here are some quicker summaries of a few pieces.
One clear characteristic of this virus is its differential impact on the elderly. A study in Italy found that 36% of deaths were of patients over 70 and 37% of patients between ages 51 and 70. On the other end, very, very few people under age 40 become infected and die. A study in Lancet looked at relatively early data from China and from other countries to attempt to characterize both the disease course and the epidemiologic characteristics. (Lancet Study) Chinese data on infection, serious illness and death rates are highly suspect and likely to be very understated, but they are some of the earliest and most complete data we have. 80% of patients in China were said to have had mild-to-moderate disease, which would not require hospitalization. About 14% developed serious disease, which likely required hospitalization and 6% needed ICU care. There was a very strong relationship between both age and presence of chronic illness and the severity of coronavirus disease. If mitigation is designed to protect the health system against resource strain, knowing the rate of serious illness is critical. Death rates are less useful for that purpose but give us a sense of the societal burden incurred as a result of the epidemic. The researchers were focused on likelihood of death, the case fatality rate. They attempted to adjust for data issues which have been widely described, including in other posts here, primarily around the impossibility of knowing the true population infection rate without widespread randomized testing. They also assumed that the infection rate was similar across all age groups, which is inaccurate. Their overall final case fatality rate best estimate was 1.38%. I believe that when the true scale of infections is known and if adjusted for variance in infection rates across age, the actual case fatality rate will be significantly lower, at least by half. And what is very notable is the constantly increasing risk going up in ten-year age bands, based on Chinese cases. For those under ten the likelihood of death was basically zero. For those aged 20 to 29, it was .03%. For those aged 40 to 49, .16%. For those aged 60 to 69, it was 1.9%, aged 70 to 79, 4.3% and 80 and over 7.8%.
A well regarded medical microbiologist in Germany wrote an open letter, and an open video, which has gone viral, expressing his concern about the socio-economic effects of shutdowns and whether they were medically necessary. (video here but in German, there are a number of sites with translations of his remarks) He asked five questions: what was the basis for projections that 5% of all infected people become seriously ill and would need ventilators; what is the basis for certainty that it is the current strain of coronavirus which is responsible for the serious illnesses being attributed to it, and not pre-existing illness; why has there not been testing of a randomized sample of the population to verify true infection rates; why are deaths being attributed to the virus when it was present, even though it may not have been a causative agent of death; and why is Italy being used as a basis for actions in Germany, when it is clearly a different case. All good questions, which should be answered in the US as well. And I admire the courage of anyone who speaks up against the inexorable machinery that is pushing massive shutdowns on the basis of sketchy evidence and ignoring the economic and non-economic harms of extreme mitigation measures.
A number of articles along these lines are appearing, but I will summarize one from the New York Times, explaining why it is almost delusional to imagine that the economy will almost magically snap back once mitigation measures are limited. (NYT Article) As the author explains, we are creating and imposing on ourselves the steepest drop in economic activity on record, bigger than the Depression. The depth of the decline alone will mean that recovery will take years. Many companies will be in a weakened financial condition, if not bankrupt, and therefor in no position to add jobs rapidly or engage in spending on expansion or new equipment. The psychological shock to consumers will change spending patterns, and consumer spending accounts for a huge percent of the economy. The stock market downturn has seriously depleted retirement savings. The effect is global, every country is suffering, and trade will see a substantial decline as well. We should never have so recklessly put these measures in place and the only by reversing them now can we minimize the looming economic catastrophe.