NEW DELHI: Different and worrying SARS-CoV-2 variants of concern, such as the UK and South African ones, appear to be converging through mutations towards a “super variant” that would confer biological advantages to the virus and make fighting the Covid-19 pandemic difficult, a new study has suggested.
This is first ever study detecting signals of a convergence, which suggests that through mutations, the UK variant is becoming more like the South African variant and vice-versa.
The scientists from the US, UK, Sweden and South Africa have shown that the emergence and rapid rise in prevalence of three independent SARS-CoV-2 “501Y lineages’’, B.1.1.7, B.1.351 and P.1, in the last three months of 2020 has prompted renewed concerns about the evolutionarily capacity of SARS-CoV-2 to adapt to both rising population immunity, and public health interventions such as vaccines and social distancing.
Viruses giving rise to the different 501Y lineages have, presumably under intense natural selection following a shift in host environment, independently acquired multiple unique and convergent mutations.
“As a consequence, all have gained epidemiological and immunological properties that will likely complicate the control of Covid-19,” noted their work.
By examining patterns of mutations the scientists found evidence of a major change in the selective forces acting on immunologically important SARS-CoV-2 genes (such as N and S) that likely coincided with the emergence of 501Y lineages.
“Our findings highlight the importance of monitoring how members of these known 501Y lineages, and others still undiscovered, are convergently evolving similar strategies to ensure their persistence in the face of mounting infection and vaccine induced host immune recognition,” they noted.
The scientists have hypothesized that other plausible contributors to the fitness advantage of viruses are that they produce more particles at anatomical sites suitable for optimal droplet or aerosol transmission.
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