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Dr Irving Kent Loh
Honest. Really. I made great efforts do not write anything about COVID while I, and undoubtedly most of you readers, have been beyond imagined happy to see COVID getting smaller and smaller in the rearview mirror as we try temporarily to return to our past lives before this pandemic disrupted all of our lives in ways that we are only now beginning to understand.
Still, a few observations have become obvious to those who pay attention and are worth highlighting, lest we begin to look back.
The first are reports from major medical centers across the country that the vast majority of COVID patients sick enough to be admitted are not vaccinated. Hospitalized patients linked to COVID are now 95 to 99% of individuals who are not fully vaccinated.
The second very worrying finding is that the Delta variant, first identified in India during its catastrophic experience with this pandemic, is now increasingly becoming the dominant form in the countries where it has appeared. Although it appears to be around 60% more infectious, it does not appear to be significantly more deadly. And the current vaccines approved in the United States against COVID offer good protection against it. Until now.
So what are the takeaways from these observations? Let’s start with the basics of biology. The first principle is that reproduction is the fundamental task of all life. What drives evolution are adaptations that occur at random in a given environment that give a mutation a survival advantage. This is a basic Darwinian observation. I leave that to those who believe there is another factor at play here as to why mutations occur to test them to live with this logic.
What connects these two observations is that continuous infections provide the substrate for mutations to occur. In biological epoch, the length of an organism’s life cycle dictates how often mutations can occur at random. The mutations that occur in turtles that have a very long lifespan are only noticeable over thousands of years and if there is little outside influence. Thus, the Galapagos tortoise has not changed significantly in millennia.
Viruses, on the other hand, replicate very quickly, and each generation of viruses has a low, but random, incidence of genetic coding errors or mutations. The vast majority of them have no survival (i.e. reproduction) benefit, so they literally die. Those that improve transmissibility, and therefore infectivity, provide a survival advantage, so these mutations, or “variations,” will eventually outperform other strains. This is why the original SARS-CoV-2 virus was replaced by the British variant, then the South African, Brazilian variant, a few others that flowered transiently, but now the Delta variant.
In the uncontrolled viral breeding environment of India’s overwhelmed health system, variant strains have undoubtedly occurred, with the Delta variant becoming the dominant strain today, due to its infectivity. As long as the virus can unleash itself in a population, mutations will occur until a “worse” mutation takes over because it reproduces better, because it is more infectious. We’ll be in trouble if it’s also more deadly (not intentionally, but as an ancillary feature). The worst-case scenario will be if the mutations also allow it to have a “vaccine escape”, meaning that our existing vaccines can no longer mitigate the infectivity and severity of the virus.
The other serious coronaviruses that have passed to humans, the original SARS-CoV-1 in 2002 and MERS in 2012, were more deadly than SARS-CoV-2 (which causes COVID-19), but much less transmissible . They therefore never became pandemics, although virologists and epidemiologists have been very attentive to this possibility. Our dissolution of our monitoring stations and the withdrawal of our epidemiologists from the former coronavirus endemic areas in 2018 allowed SARS-CoV-2 to surprise us. Our low emphasis on our testing ability allowed it to spread relentlessly until it was widely released.
So that brings us back to the first point. The approved vaccines that we have in the United States are working. They reduce the risk of becoming infected with COVID, and even if one is infected, the severity of the disease is usually not severe enough to require hospitalization and certainly greatly reduces the risk of death. Thus, the observation that patients currently hospitalized with COVID are overwhelmingly those who have not been fully vaccinated.
As long as there are those who choose not to be vaccinated, the environment conducive to mutations will exist. We are unlikely to achieve collective immunity given the number of our citizens who choose not to be vaccinated. As the apocryphal saying goes, if you are not part of the solution, you are part of the problem. So the rest of us may have to live with this virus and hope that booster vaccines can control future emerging variants of concern.
Irving Kent Loh, MD, is a preventive cardiologist and director of the Ventura Heart Institute in Thousand Oaks. Email him at [email protected].
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