COVID-19 has been with us for a long time now, and will likely continue for a while. The more time passes, viruses can acquire new mutations and change. The danger of these mutations lies in enabling the virus to escape the immune system or resist vaccines. Although this has not occurred yet, it is alarming. Hence, it is of utmost importance to know if this scenario is indeed a possibility, and when exactly it would happen. In this article, we discuss what researchers say about this topic by addressing three specific variants: B.1.1.7, 501Y.V2 and P.1.
B.1.1.7 was the first alarming variant that caused scientists’ concern; it has acquired 17 mutations at once, which is unprecedented. Its first appearance was in England in December 2020; great worries came from its higher transmissibility compared to the other circulating viruses. However, some scientists still doubt this; confirming faster transmissibility and investigating how the virus has acquired those 17 mutations simultaneously are both compelling motives to study it, as confirmed by Andrew Rambaut, a molecular evolutionary biologist at the University of Edinburgh. This variant has already spread in the United Kingdom, Ireland, and Denmark, and is still spreading quickly. The US Centers for Disease Control and Prevention published a study predicting that this variant could become the predominant variant in the US in March 2021.
501Y.V2, discovered in South Africa, has induced similar concern as the previous variant, especially that some of its mutations change its surface protein. This reduces the effectiveness of monoclonal antibodies against it; examples of these mutations include E484K and K417N. E484K has also been shown to diminish the potency of convalescent sera* ten-fold. However, Jesse Bloom, an evolutionary biologist at the Fred Hutchinson Cancer Research Center, who discovered this, stated that this does not necessarily indicate people’s immunity to this variant would be ten times weaker.
Adding even more to the concerns is the emergence of P.1 variant in Manaus, Brazil, on 12 January 2021, which was discovered by Nuno Faria, virologist at Imperial College London and associate professor at the University of Oxford. Faria’s discovery was the result of his surprise by the resurgence of COVID-19 infections in Manaus. After all, he had just co-authored a paper in Science magazine estimating the infection of three-quarters of the city’s population, which is more than enough to build herd immunity. He started then to gather samples to check whether there have been any changes in the virus causing reinfection. In the initial conclusion on virological.org, 13 out of 31 samples collected in mid-December in Manaus were a new viral variant, and they called it then P.1. This variant has appeared in places with high immunity levels, and is widely spreading; it has been detected in travelers from Brazil to Japan.
The good news is that COVID-19 is not yet resistant to vaccines; The vaccinologist Philip Krause, chairing a World Health Organization (WHO) group working on vaccines, confirms this. Yet, this rapid emergence of variants might lead at the end to vaccine-resistant variants; such scenario would dictate updating vaccines. While Krause finds this issue not urgent, Ravindra Gupta, a researcher at the University of Cambridge, demands immediately manufacturing updated vaccines to block the paths of viral changes.
*Convalescent sera: the liquid part of blood collected from patients who have recovered from an infection. Antibodies are special proteins in the plasma that have the potential to be used to fight the infection. (Source: UCLA Health).
References
sciencemag.org
virological.org