Research from the University of Notre Dame estimates that more than 100,000 people were already infected with COVID-19 by early March-when only 1,514 cases and 39 deaths had been officially reported and before a national emergency was declared. The study provides insight into how limited testing and gaps in surveillance during the initial phase of the epidemic resulted in so many cases going undetected. The study was published in the Proceedings of the National Academy of Sciences.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in thousands of deaths in the world. Information about prediction model of prognosis of SARS-CoV-2 infection is scarce. We used machine learning for processing laboratory findings of 110 patients with SARS-CoV-2 pneumonia (including 51 non-survivors and 59 discharged patients). The maximum relevance minimum redundancy (mRMR) algorithm and the least absolute shrinkage and selection operator logistic regression model were used for selection of laboratory features. Seven laboratory features selected in the model were: prothrombin activity, urea, white blood cell, interleukin-2 receptor, indirect bilirubin, myoglobin, and fibrinogen degradation products. The signature constructed using the seven features had 98% [93%, 100%] sensitivity and 91% [84%, 99%] specificity in predicting outcome of SARS-CoV-2 pneumonia. Thus it is feasible to establish an accurate prediction model of outcome of SARS-CoV-2 pneumonia based on laboratory findings.

So many of us, including me, have been focused on the failure of the federal response to Covid-19, watching President Trump's catastrophe-by-public-policy roll out day after day since late February. I've written a lot about it in these pages. In a misplaced triumphalism, some people in states that have managed to have a relatively quiet summer with low rates of Covid-19 cases have chastised those in states with renewed outbreaks as being foolish or unheeding of scientific advice, as governors still slow-walk the response to the disease and ordinary people shun masks and flock to social gatherings. We all like to think of ourselves as different, doing the right thing, doing our part.

Common Cold Study and others like it, while scrambling to understand the human immune response to SARS-CoV-2 using animals and cell cultures, along with the latest molecular techniques. They have catalogued antibody and immune-cell responses with uncommon speed, determined which are likely to be the most effective, and designed vaccines and therapies that, in animal studies and small human studies, provoke at least short-term immune responses. But there is no quick and simple experiment that can firmly determine whether immunity will be effective or lasting. It is just too soon to know.