The COVID-19 pandemic has progressed and developed over time. Multiple new variants of the disease have been documented around the globe.
Viruses are microscopic parasites that cannot survive or reproduce outside of the host body. Viruses are made up of a core of genetic material surrounded by a protective protein coat. Coronaviruses are a large family of viruses and get their name from the crown-like spikes on their surfaces.
What is a variant?
Mutations are a change to the genetic material of a genome. Viruses such as the novel coronavirus or SARS-CoV-2 are highly susceptible to mutations. Thousands of them have arisen since the first identification of SARS-CoV-2. Mutations are the method by which new variants of a strain (SARS-CoV-2) occur.
The majority of mutations will have little impact. They become worrying when the virus mutates in a way that helps the virus spread and reproduce.
Genetic analyses of SARS-CoV-2, is the virus that causes COVID-19. It has helped scientists understand how changes to the virus can impact how it spreads. Also, how it affects the people that it infects.
Variants of the original SARS-CoV-2 have emerged over the past year. In fact the dominant form of the virus circulating globally by June of 2020. It had a mutation of a DG14G substitution in the gene encoding the spike protein of the virus. The spike protein is what the virus uses to latch on to and enter human cells.
The strain with this substitution increased infectivity and transmission rate.
Recent variants of SARS-CoV-2
There are three main variants of SARS-CoV-2 circulating globally that have emerged in the last quarter of 2020.
- In the UK – a variant known as 202012/01 emerged, it is associated with increased transmissibility.
- In January of 2021, evidence was reported that this variant may be associated with increased risk of death. Especially in comparison to other variants.
- The one in Brazil – a variant known as P.1 emerged with 17 unique mutations, including three in the spike protein.
- A recent study suggested that this variant raises concerns of a potential increase in transmissibility. Or the tendency for re-infection of individuals.
- In South Africa – a variant known as 501Y.V2 has emerged.
- This variant was first identified in Nelson Mandela Bay, South Africa.
- It is already the dominant viral variant in the Eastern and Western Cape. Also in KwaZulu-Natal provinces of South Africa as well as being found in multiple countries outside of South Africa.
- There is no current evidence to suggest that this variant has an impact on disease severity.
Why are people concerned about the presence of new vaccines?
Increased infectivity and transmission rate means that more people are likely to get infected. More of those people are likely to transmit the virus to others.
Some have been concerned that many of the mutations occur in the site of the virus that vaccines target, the spike protein. However, both vaccination against the virus and natural infection of SARS-CoV-2 produce a polyclonal response that targets several parts of the spike protein. Therefore, the virus would need to accumulate several mutations in the spike protein to avoid immunity from vaccines or natural infection.
All viruses change over time, but the potential for viral mutation increases with the frequency of infection. Therefore, reducing transmission of Covid-19 through measures such as social distancing. Wearing a mask where appropriate and regular hand washing will help reduce the occurrence of mutations. Those that might benefit the virus’ infectiousness and transmissibility.