Introduction of the South African SARS-CoV-2 variant 501Y.V2 into the UK
Authors: Julian W. Tang, Oliver T.R. Toovey, Kirsty N. Harvey, David S.C. Hui
Journal: Journal of Infection (2021)

The current surge of COVID-19 cases across the UK is now thought to be mostly driven by a new, highly transmissible SARS-CoV-2 variant (B.1.1.7/ VUI-202,012/01),1Tang J.W. Tambyah P.A. Hui D.S. Emergence of a new SARS-CoV-2 variant in the UK.J Infect. 2020; 28 (S0163-4453(20)30786-6)https://doi.org/10.1016/j.jinf.2020.12.024Abstract Full Text Full Text PDF Scopus (189) Google Scholar but another highly transmissible SARS-CoV-2 variant (B.1.351/501Y.V2) from South Africa has already been detected in the UK population [https://cov-lineages.org/global_report.html]. This South African 501Y.V2 variant is characterised by three mutations in the SARS-CoV-2 spike (S) protein: K417N (a lysine to asparagine substitution at amino acid position 417 in the S protein), E484K (a glutamic acid to lysine substitution at amino acid position 484 in the S protein) and N501Y (an asparagine to tyrosine substitution at amino acid position 501 in the S protein). This last mutation is also present in the UK VUI-202,012/01 variant.1Tang J.W. Tambyah P.A. Hui D.S. Emergence of a new SARS-CoV-2 variant in the UK.J Infect. 2020; 28 (S0163-4453(20)30786-6)https://doi.org/10.1016/j.jinf.2020.12.024Abstract Full Text Full Text PDF Scopus (189) Google Scholar This 501Y.V2 variant likely emerged from the first wave of the South African COVID-19 epidemic in the hardest hit Nelson Mandela Bay metropolitan area of the Eastern Cape Province in early October 2020, then spread quickly to become the predominant virus lineage in the Eastern and Western Cape Provinces by the end of November 2020.2Tegally H., Wilkinson E., Giovanetti M., et al. Emergence and rapid spread of a new severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) lineage with multiple spike mutations in South Africa. medRxiv 2020.12.21.20248640; doi: https://doi.org/10.1101/2020.12.21.20248640Google Scholar This virus variant soon spread to neighbouring Botswana in December 2020, as well as several other countries worldwide including England, Scotland, France, Sweden, Switzerland, South Korea during December 2020, and Australia in January 2021 (Fig. 1). This phylogenetic reconstruction of the whole genome viral sequences suggests that there may have been up to 8–9 independent introductions of the 501Y.V2 variant into England and 2 into Scotland, though the details of the epidemiological linkage between these cases is unknown. One hypothesis about the origins of this variant is through intra-host viral evolution due to prolonged infection in an immunocompromised host.3Choi B. Choudhary M.C. Regan J. et al.Persistence and Evolution of SARS-CoV-2 in an Immunocompromised Host.N Engl J Med. 2020; 383: 2291-2293https://doi.org/10.1056/NEJMc2031364Crossref PubMed Scopus (725) Google Scholar Indeed, in this case report, the appearance of the E484K and N501Y mutations were described after 75 and 128 days of infection, respectively. However, this cannot be the only mechanism, as multiple other mutations are present that would require contributions from other viral lineages.2Tegally H., Wilkinson E., Giovanetti M., et al. Emergence and rapid spread of a new severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) lineage with multiple spike mutations in South Africa. medRxiv 2020.12.21.20248640; doi: https://doi.org/10.1101/2020.12.21.20248640Google Scholar Additional mutations in other viral genes may also be secondary mutations that may have arisen as 'compensatory' mutations to reduce any fitness penalty resulting from these S protein changes (K417N, E484K, N501Y).4Pond S.L.K. Wilkison E. Weaver S. et al.A Preliminary Selection Analysis of the South African V501. V2 SARS-CoV-2 clade, 2020https://virological.org/t/a-preliminary-selection-analysis-of-the-south-african-v501-v2-sars-cov-2-clade/573Google Scholar Currently, the 501Y.V2 variant is considered to be a more highly transmissible strain due to the rapidity with which it became predominant in this South African population over just a few weeks.2Tegally H., Wilkinson E., Giovanetti M., et al. Emergence and rapid spread of a new severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) lineage with multiple spike mutations in South Africa. medRxiv 2020.12.21.20248640; doi: https://doi.org/10.1101/2020.12.21.20248640Google Scholar There are also some real concerns that the mutations in the S protein (K417N, E484K, N501Y) may result in conformation changes that may impact on the effectiveness of COVID-19 vaccines developed based on earlier SARS-CoV-2 strains. However a recent small study examining the impact of the N501Y mutation on the recently licensed Pfizer-BioNTech vaccine did not show any loss of antibody neutralisation efficacy,5Xie X., Zou J., Fontes-Garfias C.R., et al. Neutralization of N501Y mutant SARS-CoV-2 by BNT162b2 vaccine-elicited sera. bioRxiv 2021 .01.07.425740; doi: https://doi.org/10.1101/2021.01.07.425740Google Scholar though similar further studies examining the impact of this N501Y and the other mutations (K417N, E484K) on the various other COVID-19 vaccines are also required. There appears to be no indication of increased severity of illness, as yet, though research is ongoing in both the UK and South Africa to further characterise the phenotype of this South African 501Y.V2 variant.6UK government. Confirmed cases of COVID-19 variant from South Africa identified in UK. 23. https://www.gov.uk/government/news/confirmed-cases-of-covid-19-variant-from-south-africa-identified-in-uk (Accessed 9 January 2020)Google Scholar Despite the presence of these two more transmissible SARS-CoV-2 variants, the public health messaging remains the same to reduce the spread of these viruses: to maintain social distancing, including masking in crowded indoor areas, and limit the number of contacts that we have each day. None. Download .pdf (.01 MB) Help with pdf files