A note from the author: This article reflects the most recent information at the time of writing (December 2020). The information provided here is subject to change as new research and data emerge on multiple fronts.

Since the emergence of the new SARS-CoV-2 variants, the world has been thrown back to the early days of COVID-19, with many unknowns and fear. Different variants have been identified at the beginning of autumn 2020, first in the United Kingdom, followed by South Africa, Nigeria and in Brazil according to the Centers for Disease Control and Prevention (CDC), though some variants selected in mink were also identified in November in Denmark, the Netherlands, Spain and some parts of the USA.[1][2] While all variants have distinct characteristics to some extent, it seems that the United Kingdom variant, B117, is of the greatest concern.

Though there is still much more to unravel, it is crucial to understand what the data provides so far and what to do next. This article will give a simplified, yet comprehensive review of what is known about the variant to date and attempt to answer some of the questions lingering in everyone’s minds.

What does B117 look like, and what changed from the original variant?

The new coronavirus strain contains 14 unique mutations and deletions, altering the amino acid sequence of the virus proteins. It may not seem like it, but 14 mutations for a virus as deadly as SARS-CoV2 are too many. And while some mutations and deletions are similar to other variants, B-117 is distinct in several ways.

One of the main concerns regarding this variant is the changes in its spike protein. The spike protein (also called S-protein) is a little extension on the surface of the coronavirus (Figure 1). In the body, this protein attaches itself onto the body’s Angiotensin-converting Enzyme2 ACE2 receptor, allowing the virus to infect the cell. In the B117 variant, the mechanism of infection is the same. However, the mutations in the spike protein allow the virus to attach itself onto the receptors and enter the body’s respiratory cells more easily.[3][4]Other mutations in the B117 also cause increased infectivity (the ability of the virus to establish an infection in the body) and virulence (ability to damage cells) in mouse models.[5]

Figure 1. SARS-CoV2 spike protein (shown in pink) binding to an ACE2 receptor. Courtesy of Roberts et al. for British Journal of Anesthesia.[6]

How are transmission, severity and symptoms affected?

In terms of severity of the disease and symptoms presented, there is no evidence that the B117 variant is any different than the pre-existing variants. However, since the B117 variant has a better ability to bind to the body’s receptors and infect, it is also transmitted more easily. Researchers estimate the B117 variant to have 56% higher transmissibility than the pre-existing variants.[7] In their initial analyses, Public Health England reported no difference in death rates for the B117 variant; however, a recent report concludes that there is a "realistic probability" of the B117 variant being associated with the increased risk of death.[8] This is alarming since it means that the virus has an increased likelihood of infecting the vulnerable members of the population, which would lead to increased deaths. It also puts a great burden on the already overloaded healthcare systems, particularly in countries with poor infrastructures.

How about the vaccine(s)?

Since B117 and the pre-existing variants have 99% the same proteins on their surface, it is very unlikely that vaccines would not give immunity against B117. Both BioNTech and Operation Warp Speed have released statements, saying they were cautiously optimistic vaccines would work against the new variant. Both companies’ investigations on the sensitivity of the variant(s) to the vaccine are ongoing.[9][10] As long as the rate of mutations is slow, and not too divergent from the pre-existing variants, there is no threat to the proper functioning of vaccines.

What have countries been doing to contain the spread of this new variant?

B117 was first identified in Kent, England, and has spread globally since then. Eight states in the U.S., as well as Denmark, Australia, Canada and many parts of Europe have reported the new variant B117.[11] Many countries have imposed new restrictions on travel from the United Kingdom, and some other countries that reported cases of B117. Stricter measures are being implemented across the globe to contain the new variant, especially considering its higher transmissibility. For some, passengers from the UK (and several others) must have a negative PCR test result, and quarantine is enforced. For others, the UK is classified a ‘red zone’, whereby travellers from there are not allowed in.[12]

How can we effectively contain the variant going forward?

Considering cases with B117 were reported in Turkey, there is a chance the B117 variant reached Northern Cyprus, which cannot be confirmed due to the lack of sequencing/genotyping, which aims to investigate the genetic information of the virus, including the changes from previous variants. To effectively contain the variant, we must remember that viruses are non-living organisms. To reproduce and mutate, they must have a host. Therefore, it is incredibly important to continue wearing masks, social distancing and abiding by the public health advice from experts. Except for not allowing the viruses to live inside us, there is not much we can do to prevent them from mutating.

So, do we worry about new variants?

The answer is unclear. Virologists point out that as long as the rate of mutations is slow, and do not "outdo" vaccine efforts, we should be good. The real problem begins when the virus mutates to a great extent, which is only possible if we cannot contain the spread. And in that case, yes, do worry about new variants.[13]

References

[1] Centers for Disease Control and Prevention. Emerging SARS-CoV2 Variants. https://www.cdc.gov/coronavirus/2019-ncov/more/science-and-research/scientific-brief-emerging-variants.html (2021).

[2] Rambaut, A., Pybus, O.G., Robertson, D.L., O’Toole, A., Loman, N., Brown, I., Hiscox, J., Horby, P. & Barclay, W. NERVTAG. Risk assessment of SARS-CoV-2 variants that have been selected in mink. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/938979/S0878_Risk_assessment_of_SARS-CoV-2_variants_that_have_been_selected_in_mink.pdf. (2020).

[3] Rambaut, A., Loman, N., Pybus, O., Barclay, W., Barrett, J., Carabelli, A., Connor, T., Peacock, T., Robertson, D.L. & Volz, E.  Preliminary genomic characterisation of an emergent SARS-CoV-2 lineage in the UK defined by a novel set of spike mutations. https://virological.org/t/preliminary-genomic-characterisation-of-an-emergent-sars-cov-2-lineage-in-the-uk-defined-by-a-novel-set-of-spike-mutations/563 (2020).

[4] Peacock, T. et. al The furin cleavage site of SARS-CoV-2 spike protein is a key determinant for transmission due to enhanced replication in airway cells. bioRxiv. https://doi.org/10.1101/2020.09.30.318311. (2020).

[5] Gu, H. et al. Adaptation of SARS-CoV-2 in BALB/c mice for testing vaccine efficacy. Science, 369, 1603–1607 doi:10.1126/science.abc4730 (2020).

[6] Roberts, C. M., Levi, M., McKee, M., Schilling, R., Lim, W. S., & Grocott, M. P. W. COVID-19: a complex multisystem disorder. British Journal of Anaesthesia, 125, 238-242 https://doi.org/10.1016/j.bja.2020.06.013. (2020).

[7] Davies, N., Barnard, R., Jarvis, C., Kucharski, A., Munday, J., Pearson, C., Edmunds, J. Estimated transmissibility and severity of novel SARS-CoV-2 Variant of Concern 202012/01 in England. SSRN Electronic Journal, 1–24. Retrieved from https://www.medrxiv.org/content/10.1101/2020.12.24.20248822v1.full.pdf (2020)

[8] Horby, P., Huntley, C., Davies, N., Edmunds, J., Ferguson, N., Medley, G., Hayward, A., Cevik, M. & Semple, C. NERVTAG Paper on COVID19 Variant of Concern B117 (2021).

[9] Bloomberg. BioNTech CEO Confident Vaccine Will Work on U.K. Covid-19 Variant (2020).

[10] Seeking Alpha. Will vaccines work against the U.K. coronavirus variant? (2020).

[11] Al Jazeera. Which countries have reported new variants of COVID-19? (2020).

[12] CNN. UK travel ban: These countries have imposed new restrictions (2020).

[13] Bollinger, R., Ray, S.  Johns Hopkins University School of Medicine. A New Strain of Coronavirus: What You Should Know (2021).

Photo: Victor Allan, Flickr.