## A. Is CoVID-19 Dangerous?

The virus started in Wuhan, China in late 2019.  The World Health Organization (WHO), on December 31, 2019, reported that a new virus was detected in China, but that there was no evidence of human to human transmission.   On January 22, 2020 the WHO announced that there was indeed evidence of human to human transmission.  However, by this time the virus had spread throughout the world via air travel.

The media was suddenly flooded with pictures of hospitals in China being constructed in large fields, people dying in Italy and large groups of people being quarantined.  Then COVID-19 deaths began to appear in New York City.  Figure 1 illustrates the weekly deaths.

Figure 1.  This is a plot of the weekly deaths from Influenza  and Pneumonia in New York State.  The horizontal axis is the weeks from October 2015 to April 2020.  This data was from the CDC.

The right hand side of Figure 1 shows a dramatic increase in the weekly death, rising from 200 per week to 1000 per week.

State and Federal Governments sprang into action.  The Federal Government assisted states with construction of hospital rooms and the rallying of private business to supply protective equipment and ventilators. They also began working with the FDA to shorten the time for the development of vaccines, they authorized the use of potential viral drugs, and more.  States enacted massive isolation regulations.

The New York graph is important and instructive, but it is only one data point.  It may not be representative.

The following Figure 2 is a plot of the daily deaths in the United States.  They peaked on April 21, 2020 and are now heading downward.  The “R2”number refers to the number of missing variables.  A number below 0.9 indicates that a large number of variables are missing.  The R² value of .76 is a poor and unreliable fit to the data.  It is to be used only to assist in determining general trends.

Figure 2.  Is the daily COV-19 deaths per day in the United States.  The vertical axis is the number of deaths and the horizontal axis is the number of days from 3/21/2020 until May 11, 2020.  The curve is a trend line based on a 2 level polynomial equation.  The data was obtained from www.worldometers.info

The figure illustrates wide variations when daily numbers are used.  A weekly chart displays a smoother more uniform curve.  There is an interesting observation.  After April 19th  the up slopes were consistently two days and falling around the weekend.  Most of the down slopes were 5 days.  This anomaly could be related to a delay in reporting as opposed to increased weekend deaths.

The latest study by the CDC suggests that the morbidity of COVID-19 is similar to or lower than the 2018 influenza/pneumonia statistics.   But in determining how dangerous a disease is depends on more factors than its death rate.   It also depends on the disease contagiousness.   COVID-19 is 2.5 times more contagious than the normal influenza.