SARS-CoV-2 is known to have mutated and different strains are going around the globe. In a recent preliminary study that has not been peer-reviewed, scientists have identified 14 mutations in Spike protein and counting.
Spikes on a virus are responsible for binding and entry into host cells and is a major target of neutralising antibodies.
The scientists from Los Alamos National Laboratory, USA; University of Sheffield; Sheffield Teaching Hospital NHS Foundation Trust; and Duke Human Vaccine Institute, North Carolina, USA stated that the mutation [ihc-hide-content ihc_mb_type=”show” ihc_mb_who=”2,3,5″ ihc_mb_template=”1″ ]Spike D614G began spreading in Europe in early February and became dominant in these regions. They also presented evidence of recombination between the mutated strain and locally circulating strains, indicative of multiple strain infections.
Their studies revealed that viruses bearing the mutation -Spike D614G – are replacing the original Wuhan form of the virus rapidly and repeatedly across the globe. This mutation is found mostly in the UK, in both England and Wales, and also in Australia. They also indicated mutations take place in local region, different geographical regions, and different gene sequences encode for the same amino acids, among other variations.
Through March, the G614 strain became increasingly common throughout Europe, and by April it became dominant. In North America, infections were initiated and established across the continent by the original D614 form, but in early March, the G614 was introduced into both Canada and the USA, and by the end of March it had become the dominant form in both nations.
Asian samples were completely dominated by the original Wuhan D614 form through mid-March, but by mid-March in Asian countries outside of China, the G614 form was clearly established and expanding. The scientists involved in this study voiced their concerns that D614G mutations may increase transmissibility, it might also impact severity of disease.
This study revealed that viruses bearing the mutation Spike D614G are replacing the original Wuhan form of the virus rapidly and repeatedly across the globe. What is driving this selective mutation is unknown.
The paper discusses many other mutations that is taking place in this virus in different regions. Global Initiative for Sharing All Influenza Data (GISAID) for SARS-CoV-2 sequence database was used as a baseline resource. GISAID is the primary COVID-19 sequence database resource where international groups contribute to this global effort.
Scientists focus on the spike because it mediates infection of human cells and is the target of most vaccine strategies and antibody-based therapeutics. These mutations may confer selective advantages in transmission or resistance to interventions, making the battle harder to fight. If the virus continues to mutate, it will take more time to deliver the first vaccine.
Ignoring important evolutionary transitions in the virus could ultimately limit the effectiveness of the first vaccines for clinical use. Over 62 vaccine approaches are currently being explored, and a wide variety of candidate SARS-CoV-2 vaccines are in development.
Coronavirus itself is not new to humans. In the last decades, the world faced three major outbreaks caused by beta coronavirus. Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) in 2002, infected over 8,000 people and killed 800; followed by Middle East Respiratory Syndrome, MERS-CoV in 2012, a difficult to transmit but highly lethal virus, with 2,294 cases as of 2019, and 35 per cent mortality; and now SARS-CoV-2 is causing the severe respiratory disease COVID-19.
Covid-19 is feared due to three factors, human beings have no direct immunological experience with this virus, leaving us vulnerable to infection and disease; it is highly transmissible; and it has a high mortality rate.
The paper was published in BioRxiv, a preprint server for biology.
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