COVID-19 is getting less deadly

The Swedish COVID-19 statistics, as published by Worldometer, suggest that COVID is simultaneously becoming more communicable and less deadly.  To see the latest, check out the Daily New Cases and the Daily Deaths on the Worldometer webpage for Sweden.  Daily New Cases are rising, suggesting that the disease is getting more communicable.  Meanwhile, Daily New Deaths are falling, suggesting that the disease is getting less deadly.

These results are not surprising to those who know about The Evolution of Virulence (PDF) in infectious diseases.  Viruses, not having DNA, do not reproduce themselves as precisely as do higher organisms.  As a result, there is much more genetic variation within their descendants, resulting in rapid evolution, which:

  1. Increases Communicability.  Natural selection favors those virus components that allow the virus to spread to more hosts.
  2. Reduces Deadliness.  Natural selection disfavors those virus components that cause the host to die, because a dead host cannot spread the disease.

These factors have been studied extensively in wild populations of the animal world.  The first causes the infectious period of a virus to lengthen.  The second causes the virus to become less deadly.  As a result, almost all viruses found in wild populations are intermediate in severity.  They are neither so strong that they debilitate the host nor so weak that the host can quickly overcome them.

We have excellent examples of intermediate-severity viruses in the human world — a bunch of different viruses known as the "common cold."  They are not so strong that they kill or debilitate, nor so weak that they can be overcome in less than a week.

The public health authorities have been selecting for decreasing viral symptoms and thus decreasing deadliness in COVID-19.  People who display obvious symptoms are getting tested for the virus and then isolated so that they cannot spread the virus to others.  A virus without obvious symptoms can hardly be deadly!

As I noted at the beginning of this posting, the Swedish charts clearly suggest that COVID-19 is becoming more communicable but less deadly, just as scientific theory would expect.  But what about COVID-19 in the United States?  At first glance, the Worldometer webpage for the U.S. appears to show that more and more people are getting the disease and that more and more people are dying of it.

But our Worldometer death statistics are collected differently from the way they are collected in Sweden.  In the U.S., we get our death reports from hospitals, and we pay hospitals more money if COVID is included as one of the possible contributors to the death.  As a result, our statistics show death with COVID, not death by COVID.  If we used the same method to calculate deaths by common cold, we might conclude that the common cold becomes a deadly disease during sniffles season!

Fortunately, the CDC publishes another set of data (the Excess Death data), which allows us to separate out death by COVID from death with COVID.  In the graph below I have plotted, in red, the Deaths with COVID published by Worldometer and, in blue, the Excess Deaths published by the CDC.

The CDC first calculates expected deaths by averaging the number of deaths for the same week over the last three years.  Then it calculates Excess Deaths by subtracting the expected deaths from the actual deaths.  I have added a third step: I have divided the Excess Deaths by 10 so they would fit on the same scale as the Deaths with COVID.  The results are displayed in the graph below:

Beginning August 15, there has been a clear divergence between the trends of the two sets of data.  In recent weeks, Deaths with COVID have been rising, while Excess Deaths have been falling.

The most recent week, the one that ended on November 7, was the first week since the epidemic began in which Excess Deaths were negative.  But that week's death count will almost certainly be revised upward, as the CDC notes:

It is important to note that it can take several weeks for death records to be submitted to National Center for Health Statistics (NCHS), processed, coded, and tabulated.  Therefore, the data shown on this page may be incomplete, and will likely not include all deaths that occurred during a given time period, especially for the more recent time periods.

In both the U.S. and Sweden, COVID-19 is following the disease course predicted by scientific theory.  The communicability of COVID has been rising, as shown by rising Daily New Cases, while the deadliness has been falling, as shown in the U.S. by falling Excess Deaths and in Sweden by falling Daily Deaths.

But even though COVID-19 is weakening, these data show that it is still deadly.  This is true in both Sweden and the United States.  So don't start acting recklessly!  If you have symptoms, isolate yourself.  Don't spread COVID to others!

You won't read about COVID weakening in the Democrat Party's media (i.e., the mainstream media and social media) until the presidential election has been decided.  They need to pretend COVID is still extremely deadly, or their lame excuses for cheating would crumble (such as their claim that "social distancing" concerns prevented them from letting Republican poll-watchers get close enough to see what was going on).

But the science cannot be denied. Deadly viruses eventually evolve into more communicable but less deadly forms.  COVID-19 is no exception.

Howard Richman blogs at  He co-authored the 2014 book Balanced Trade: Ending the Unbearable Costs of America's Trade Deficits, published by Lexington Books.