Tuesday, March 24, 2020

Combating the Evolution of SARS-CoV-2 (novel coronavirus)

My fans have been wondering why I have not been commenting on the unfolding crisis. But I have! See my posts on AIER: https://www.aier.org/staff/robert-e-wright/

1. Should Government Go Medieval During Pandemic Disease? Hint: No!
2. The Parasites Exacerbating COVID:  "Instead of identifying and focusing on its core mission, the government, like any good parasite, has bloated and stretched itself into so many areas that it is over-extended. Instead of doing a few key things well, it does many, many things it shouldn’t be doing at all, and usually poorly at that."
3. Revolution Is In the Air: Warns that if basic services goes down and the lock downs are not working to quell the pandemic, things could get "real" real quick.
4. The Columbia-NYT Model Can't Be Right: Critiques one of the more dire predictions of the virus spread with math (it seems to use an exponential rather than a logit or epi function) and intimate knowledge of South Dakota.
5. Government Common Stock Ownership: Cure Worse Than Disease: Argues on Jacksonian grounds that the federal government/Federal Reserve should not buy common shares in corporations.
6. Look also for still forthcoming articles on life insurance and Social Security and the coronavirus crisis.

In this post, original to this blog, which I want to keep alive with original content whenever I can muster some, I offer some thoughts on the biological evolution of SARS-CoV-2 and the best policy for minimizing its future impact, which is to match evolutionary process with evolutionary process.

Combating the Evolution of SARS-CoV-2 the Novel Coronavirus

Scientists cannot know how SARS-CoV-2, the virus that causes COVID-19, will evolve, only that it will change in the face of selective pressures. They used to believe that pathogenic lethality faced natural limits but now are not so sure. That, however, is no reason to panic as markets can keep pace with viral mutation. In many ways, market participants and viruses are subject to similar evolutionary processes. What must be combated are attempts to centrally plan the response to SARS-CoV-2’s inevitable evolution.
In a famous 1950 article in the Journal of Political Economy entitled “Uncertainty, Evolution and Economic Theory,” American economist Armen A. Alchian argued that the firms that come closest to maximizing profits, even if due simply to dumb luck, are the most likely to survive.
In the biological world, those organisms that maximize the production of reproductively successful offspring are also the most likely to survive, even if the organisms themselves know nothing of what they are doing. No intelligent design, or plan, is necessary as the environment, the set of constraints and conditions faced by firms or organisms at any given moment, selects the winners and weeds out the losers.
Epidemiologists (scientists who study the spread of disease) try to discover which viruses and other pathogens will be selected in different environments, including human bodies. For a long time, they believed that the virulence of viruses faced natural limits because pathogens that killed their hosts were less likely to spread to new hosts than were ones that merely made their hosts ill.
Happily, many pathogens do evolve to become more benign. However, two other key variables, ease of transmission and recovery time, complicate matters. Pathogens can evolve to become more easily transmitted to other hosts, like through the air, or to linger longer in their hosts. In both those cases, pathogens can become more deadly without diminishing their chance of being transmitted to a new host (person!) before the original host perishes. In the first instance, the chance of infecting a new host increases and in the second, the number of opportunities to infect a new host grows.
In short, scientific models alone cannot predict the evolutionary path that a particular pathogen will take. Evolution may drive it towards reduced virulence but it might also make it easier to transmit or more difficult to shake off, which in turn could allow increased virulence without reducing the production of successful offspring.
To gain some insights into the possible evolutionary paths of pathogens, and strategies for their containment, scientists study epidemiological history. Even a brief survey reveals large variations in pathogenic evolution and the outcome of human responses to it.
Variola major (smallpox), for example, could kill one in three of the adults it infected because it spread relatively easily in two phases, first by causing vomiting and then by forming pustules that covered the host pretty much head to toe. It killed about half a billion people in the century before its eradication, which incidentally in most places was brought about by herd inoculation, not quarantine.
Tuberculosis (TB), by contrast, remains a scourge of Biblical proportions. It lays dormant in about 2 billion people worldwide and will emerge with active symptoms in about 10 million every year. It can be cured with a course of drugs but of course drug-resistant strains are appearing due to selective pressures. Johnson & Johnson is on the case, though, developing an entirely new type of anti-TB drug.
Cholera is also highly virulent, spreading by causing massive diarrhea that can quickly lead to death. It is best prevented through modern sanitation so in less developed nations or places where water systems have gone done due to war or catastrophe outbreaks remain common and deadly. Some 9,000 people died of the disease, for example, after the earthquake that struck Haiti in 2010.
The bubonic plague responsible for the Black Death that killed about a third of the population of parts of Europe in the medieval period also remains extant but it is treatable with antibiotics. Untreated, it can kill up to three in five of the humans it infects because reservoirs of this nasty bug live on in rodents. Marburg and Ebola can also remain deadly to humans because they find safe harbor in bats. Both spread through secretions, so they evolved to cause vomiting, diarrhea, and late stage hemorrhaging in their victims. MERS, which kills about a third of those it infects, also harbors in bats but also in camels.
Yellow fever, which killed about 10 percent of the total population of Philadelphia in 1793, is also highly virulent but spreads only via infected mosquitoes, not person to person. Mosquito suppression and herd inoculation have eliminated it from the United States but epidemics still occur in Africa and, less frequently, in South America. Much the same could be said of dengue, which kills about 50,000 people a year globally, and P. falciparum, more commonly known as malaria (which is a parasite rather than a virus).
Perhaps the most virulent infectious disease, rabies, still kills some 70,000 people a year worldwide. Almost nobody survives once the infection, caused by the rabies virus, progresses. Vaccines and treatments, however, can save most victims if they are treated soon enough after being bitten by an animal carrier. Human to human transmission is of course rare.
SARS-CoV-2, by contrast, spreads easily from person to person. At present, it is not, however, highly virulent except in people already suffering from other serious maladies
As noted above, SARS-CoV-2 will evolve and could become more virulent in the process. But it could also become less virulent and/or more difficult to transmit. Of course any mutated forms will have to spread from host to host again and with proper incentives vaccines should be available by then, as they are for the flu and many other contagions. 
Ultimately, to combat the evolution of SARS-CoV-2 effectively over the medium and long term we need to nourish another evolutionary form, the free market. Instead of restricting competition and imposing top-down plans, government should let a thousand firms bloom, as South Korea has. Most experiments will fail but a few, if only out of dumb luck, will find a way to check SARS-CoV-2 regardless of its evolutionary path.

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