If you’re looking for some fun summer beach reading, I can’t recommend this article, The origins and potential future of SARS-CoV-2 variants of concern in the evolving COVID-19 pandemic. It’s a summary of the past year of the pandemic.
One year into the global COVID-19 pandemic, the focus of attention has shifted to the emergence and spread of SARS-CoV-2 variants of concern (VOCs). After nearly a year of the pandemic with little evolutionary change affecting human health, several variants have now been shown to have substantial detrimental effects on transmission and severity of the virus. Public health officials, medical practitioners, scientists, and the broader community have since been scrambling to understand what these variants mean for diagnosis, treatment, and the control of the pandemic through nonpharmaceutical interventions and vaccines. Here we explore the evolutionary processes that are involved in the emergence of new variants, what we can expect in terms of the future emergence of VOCs, and what we can do to minimise their impact.
Oh, right, I really don’t want to hear about how “several variants have now been shown to have substantial detrimental effects on transmission and severity of the virus”, but they do, and it’s a worry. Here, for example:
So the reassuring (and unsurprising) fact is that the virus isn’t really being selected directly for lethality. Doesn’t that make you feel better? All the virus ‘cares’ about is increasing the number of viruses, of increasing the viral load, and it could do that by having milder effects on their host. The B.1.1.7 variant isn’t doing that. It is increasing the load in your cells with no ameliorating mutations, and so is having more severe effects.
In case you were wondering, B.1.1.7 is going by the common name of the Alpha variant. It’s not nice. At the end of that excerpt, it says a bit about the B.1.167.2 variant, which is even nastier, with 64% greater transmissibility. You probably know it better as the Delta variant, which is now the dominant strain in the US.
You know there are also Beta, Kappa, Theta, and Zeta variants, right? I can’t keep track of them all. I guarantee that more will be arising. Isn’t evolution amazing? If only we lived in a country where the power of evolution was appreciated.
The article tries to be encouraging in its conclusion.
As COVID-19 transitions from a pandemic to an endemic disease, VOCs present new global challenges to health by virtue of increased transmissibility and virulence and evasion of natural and vaccine-induced immunity. In this article we have explored the selective forces that shape how VOCs emerge and become established. We also identify possible steps that we can take to limit their emergence and, when they do arise, their impact. Moving forward, we must also consider how SARS-CoV-2 transmits to and amongst other animal species, placing both them and us at further risk. It will therefore be important to adopt a multidisciplinary One Health approach for future pandemic management that accounts for the interrelated nature of human, animal, and ecosystem health.
Oh, good, steps to limit the emergence and impact of variants…[quickly flips back a few pages to see what those are].
More broadly, we can reduce the rate of emergence of new VOCs and slow the spread of existing ones by reducing overall case numbers through vaccination at a global scale and by maintaining or enhancing the non-pharmaceutical interventions that have contributed to controlling the pandemic (case detection and isolation, contact tracing and quarantine, masking and personal distancing, and improved ventilation). Having low case numbers makes it easier to test and genotype a high fraction of cases and increases the efficacy of contact tracing measures to stop onward transmission. Furthermore, mathematical models predict that measures that reduce contact rates with susceptible individuals will not only slow the spread of SARS-CoV-2 overall but will also reduce the relative advantage of variants that have a transmission advantage. Thus, the measures taken to reduce contacts and limit the number of COVID-19 cases may have the added benefit of slowing the rate at which VOCs with a transmission advantage overtake the wildtype. This predicted pattern, with selection weakening as stringency measures are increased, appears to be borne out in data for B.1.1.7 from England and British Columbia.
So, all we need to do is vaccinate everyone, keep wearing masks and maintain social distancing…how is that working out for you, America? It’s basic stuff, it’s all within our reach, but it’s Republican policy to deny every one of those actions. Keep it in mind that their policies aren’t just killing their constituents, they’re also increasing the likelihood of new variants that will harm non-Republicans, even in Democratic states, and even in foreign countries that want nothing to do with our contemptible politics.
To be fair, I shouldn’t blame only Republicans. My university is opening up in the fall with no vaccination requirement, and is debating reducing the social distancing requirement.