As worldwide efforts to deploy the different vaccines against COVID-19 take shape, some unpredictable obstacles have appeared. One of the most important ones is the confirmation of several new variants of SARS-CoV-2, the virus that causes COVID-19. 

Coronavirus Mutations: An Ever-Looming Hazard

The latest uptick in transmission rates has provided a fertile ground for new coronavirus mutations to arise. Furthermore, as the virus is now present all around the world, in geographically separated areas, the onset of genetically distinct variants was also expected.

Currently, there are several thousands of variants of SARS-CoV-2 circulating around the world. Most of these are essentially the same as the original 2019 strain of SARS-CoV-2 (often referred to as the “wild strain”).  However, three variants of special concern appear to behave differently. They are all more transmissible, but the full extent of their differences is still being determined.

Below, we will share some information on these three variants:

Comparison of the current variants of concern

Name of the strainLocation of first detectionTransmission rate*Other features of note
P.1Manaus, Brazil120% higherIncreased chance of reinfection
B.1.1.7Kent, United Kingdom75% higherHigher mortality rate
B.1.351Nelson Mandela Bay50% higherLowered efficacy of protein-spike dependant vaccines

* (compared to initial “wild” strain)

Variant P.1 (The Brazil strain)

Variant P.1 was originally detected in the Brazilian city of Manaus in December 2020. Its presence was confirmed on January 12th, 2021 by a team of Brazilian and Japanese researchers (Variants of concern or under investigation: data up to 22 March 2021, 2021). At this time, the city of Manaus was experiencing an unprecedented resurgence in both new infections and fatalities related to COVID-19 (Sabino et al., 2021). 

Variant P.1 seems to have already spawned two new lineages of SARS-CoV-2. One of the most notable aspects of this variant is that it seems to cause viral loads up to 10 times higher as those from other variants (Naveca et al., 2021). Furthermore, this variant seems to be capable of evading the immunity gained from past infections, and it has been noted to have a reinfection rate up to 61% higher than that of the “wild” strain (Faria et el., 2021). The presence of variant P.1 is now confirmed in 31 different countries.

Variant B.1.1.7 (The U.K. variant)

Sometimes also known as the “Kent variant”, this variant was first identified in early December 2020, although it is believed to have emerged around September 2020.

This strain has garnered particular attention because its transmission rates seem to be 75% higher (Leung et al. 2021). In March, the British Medical Journal published a cohort study showing that the B.1.1.7 variant has a higher mortality rate than the “wild” variant, of up to 2.5 to 4.1 deaths per 1000 detected cases. It also carries an increased risk of hospitalization (Challen et al. 2021). 

The presence of this variant has now been confirmed in 118 countries. It is now the dominant strain across the United Kingdom and in most countries in Europe.

Variant B.1.351 (The South Africa variant)

This variant was originally detected in October 2020. It shares some key genetic similarities with B.1.1.7, suggesting a common lineage. 

This variant was first identified in the city of Nelson Mandela Bay. It is believed that it may have emerged as early as July 2020. However, as South Africa does not routinely perform whole genome sequencing, it may have evaded detection until it became the dominant strain in the region (Tegally et al. 2021).

Just like the other two strains studied, variant B.1.135 seems to have a higher transmission rate, especially among young and healthy individuals. Finally, this variant carries the risk of diminished vaccine efficacy. This is because this variant has a mutation in one of its spike proteins, which can help it escape from neutralising antibodies. 

The presence of this variant has now been confirmed in 67 countries.

A Note on Naming Practices

For this article, we have identified each strain using both the lineage nomenclature preferred by the Centers for Disease Control (CDC), as well as its colloquial name. The latter is often based on the location on which each variant was originally discovered. 

However, using place names to identify viruses or strains is likely to be inaccurate and could be harmful. We still don’t know the exact location of patient zero for any of these variants. The practice of linking viruses with specific locations can stigmatize countries, create geopolitical backlash, and prevent countries from reporting their case numbers accurately (Karim & Loots, 2021).

Final Thoughts

COVID-19 is a rapidly changing situation, and so is the information available about its variants. When drafting this article, we consulted a series of studies that have been published or presented to high-impact journals. However, some of these are still on the pre-print stage. As more information becomes available, some of the conclusions presented may change.

The unpredictability of this situation should serve to highlight the importance of a coordinated and equitable vaccination campaign worldwide.


Challen, R., Brooks-Pollock, E., Read, J. M., Dyson, L., Tsaneva-Atanasova, K., & Danon, L. (2021). Risk of mortality in patients infected with SARS-CoV-2 variant of concern 202012/1: matched cohort study. bmj, 372.

Faria, N. R., Mellan, T. A., Whittaker, C., Claro, I. M., Candido, D. D. S., Mishra, S., … & Sabino, E. C. (2021). Genomics and epidemiology of a novel SARS-CoV-2 lineage in Manaus, Brazil. medRxiv

Karim, S. S. A., de Oliveira, T., & Loots, G. (2021). Appropriate names for COVID-19 variants. Science, 371(6535), 1215-1215

Leung, K., Shum, M. H., Leung, G. M., Lam, T. T., & Wu, J. T. (2021). Early transmissibility assessment of the N501Y mutant strains of SARS-CoV-2 in the United Kingdom, October to November 2020. Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin, 26(1), 2002106.

Naveca, F., Nascimento, V., Souza, V., Corado, A., Nascimento, F., Silva, G., … & Bello, G. (2021). COVID-19 epidemic in the Brazilian state of Amazonas was driven by long-term persistence of endemic SARS-CoV-2 lineages and the recent emergence of the new Variant of Concern P. 1.

Public Health England. 2021. Variants of concern or under investigation: data up to 22 March 2021. [online] Available at: <> [Accessed 23 March 2021].

Sabino, E. C., Buss, L. F., Carvalho, M. P., Prete, C. A., Crispim, M. A., Fraiji, N. A., … & Faria, N. R. (2021). Resurgence of COVID-19 in Manaus, Brazil, despite high seroprevalence. The Lancet, 397(10273), 452-455

Tegally, H., Wilkinson, E., Giovanetti, M., Iranzadeh, A., Fonseca, V., Giandhari, J., … & de Oliveira, T. (2020). 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.

Jennifer Billings is the Medical Editor at National Coronavirus Hotline(NCH). She is an Integrated medical doctor who has been published on NCH Blog, and is a regular contributor at MedCity News, Physician Family, and Psychology Today.