COVID-19 Variants


What is a virus?

A virus is a genetic code enveloped in a lipid and protein capsule and, for example in the case of SARS-CoV-2, multiple spikes with receptors and enzymes allowing for binding to, and penetration into, the host cell. It is inanimate and does not need to feed itself to survive. The ensuing disease, such as COVID-19, is a potential side-effect of you encountering the virus. The “ideal virus” is one that transmits itself rapidly to as many as possible without actually killing its host.

What is a new variant?

A new variant is a result of viruses undergoing mutations as they replicate. The different variants may or may not have different consequences after infection.

Several new variants have been identified, in the UK – B.1.1.7 in South Africa 501Y.V2 and in Brazil a variant belonging to the B.1.1.28 group.

It is expected many more variants will be identified, some of which may be more transmissible, potentially cause more severe disease, and / or evade current vaccinations. Researchers are carefully studying the genetic variations, particularly those that are becoming more common in certain locations. (a project at Scripps Research supported by the National Institute for Allergy and Infectious Diseases, National Center for Data to Health, and Centers for Disease Control and Prevention has a dashboard of variants. The dashboard allows customisable reports by variant, location and time.

What does UK B.1.1.7 or VOC-202012/01 mean?

The UK B.1.1.7 is the variant identified in the UK. It is also called VOC-202012/01 (VOC stands for Variant of Concern 2020 – the year, 12 the month).

What is the variant from South Africa called?

The variant identified in South Africa is called 501Y.V2 because of the N501Y mutation they found in the spike protein that the virus uses to gain entry into cells within the body. This variant is also known as B.1.351.

What is the "Brazilian" variant?

Several variants have been reported in Brazil. The variant, known as "P.1", was identified in Manaus in January 2021, and is a "descendant" of the "B.1.1.28" variants. They have been detected in countries outside Brazil. The P.1 may be more transmissible than previous strains circulating in Brazil. 

Are the variants (UK B.1.1.7 and 501Y.V2) the same?

Although the two identified variants share a number of similar mutations, the South African variant harbours multiple mutations at the same time, such as the E484K mutation at one location of the spike protein, as well as the K417N mutation at another, among others.

If the spike protein accumulates too many mutations, it may become unrecognizable to the immune system. These mutations don't make the new variant invincible, only less vulnerable to attack by some individuals’ antibodies.

There’s still a lot we don’t know about the new strains, although they are being investigated. Both appear to be more transmissible.

What are the concerns about the variant strains?

Scientists claim that both the South African and UK variants appear to be associated with a higher viral load, meaning a greater concentration of virus particles in patients' bodies, possibly contributing to more effective and thus increased transmission.

It has even been estimated that the B.1.1.7 variant has a reproduction number (R0) ranging between 0.4 and 0.7 higher than the non-VOCs. As a result more people can get infected which could subsequently mean an increase in absolute numbers of infections, thus more sick people and even an increased number of fatalities, either due to the virus’ direct effect itself (in the case of severe to fatal Covid-19 disease) or indirectly due to the fact that the Healthcare Systems are overwhelmed.

How do the variants impact an individual’s immunity?

There is substantial variation in the impact of mutations both among individuals and within the same individual over time. Extensive person-to-person variation in how well the antibodies stop the virus from infecting cells, could potentially affect how vaccines against COVID-19 work.

The consequence of escaping vaccine-induced immunity may produce "greatly reduced susceptibility" to protection from antibodies derived from previously challenged and immunised individuals.

Will the vaccines be effective against the new variants?

Vaccination produces a ‘polyclonal’ response that targets several parts of the spike protein. The virus would likely need to accumulate multiple mutations in the spike protein to evade immunity induced by a vaccine. There is currently no evidence to suggest COVID-19 vaccines won't protect against both B.1.1.7 and 501Y.V2. If, as ascertained by preliminary studies, neutralizing function is indeed diminished but not eliminated, then it could suggest that a strong vaccine response will protect against the variant.

It would likely take years, not months, for the coronavirus to mutate enough to “outwit” current vaccines and become resistant to them. Vaccines might become gradually less effective over time, rather than suddenly not working.


bioRxiv preprint doi: version posted January 4th, 2021

Comprehensive mapping of mutations to the SARS-CoV-2 receptor-binding domain that affect recognition by polyclonal human serum antibodies