COVID 19 Variants of Concern

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COVID 19 has ravaged the world for more than a year, and finally, we are seeing the emergence of preventive measures and treatments, like vaccinations and monoclonal antibodies. However, the COVID 19 virus has evolved and mutated to become more complex than anyone ever thought it would, with certain variants having an infectivity rate of over 150% compared to the original Wuhan strain. All of these variants have their own unique and deadly characteristics that lead to them being more deadly and infective than ever expected.




The 4 main variants that will be discussed are the B.1.1.7 Variant, the 501Y.V2 variant, the P.1 Variant, and the B.1.617.1/B.1.617.2 Variants. The first major variant that was identified was the B.1.1.7 variant, first discovered in the UK. This variant was considered to be one of the most infective mutations of COVID when first discovered, causing the UK to enter a state of a national lockdown. This had a 74% higher infectivity rate compared to the original Wuhan variant, which is staggeringly high compared to the 20% higher infectivity rate of the far less infective US variant discovered in June 2020. This variant was considered to have crucial mutations in the Amino Acid codons that allowed it to be much more infective than the Wuhan variant and the US variant. The two codons that allow the B.1.1.7 variant to be so infective are the D614G mutation and the N501Y mutation. So, what do those numbers and letters mean? The D614G mutation is the swapping of aspartic acid and glycine in position 614 on the SPIKE protein, and the N501Y mutation is the swapping of asparagine to tyrosine in position 501. Furthermore, these mutations cause drastic changes in the transmission of COVID 19. The D614G mutation has a moderate effect on transmissibility, allowing the virus to infect people easier. Additionally, the N501Y allows for the SPIKE protein to bond easier with the ACE2 receptor on the human respiratory cells. Both of these mutations play a key role in the infectivity of the B.1.1.7 variant. 





The next variant originated in a continent that has had many epidemics previously: Africa. The 501Y.2 variant originated in South Africa. Due to the destruction caused by these variants, South Africa was forced to enter a state of lockdown to try to slow the spread of the virus. All three of these variants have unique mutations on the SPIKE protein that allow it to cause such destruction. The first of these to arise was the 501Y.2 variant, also known as the B.1.351 variant. Although not being as highly transmissible as the B.1.1.7 variant, it still was 50% more transmissible compared to the original Wuhan strain. However, this strain had a unique characteristic that allowed it to stay longer in people’s bodies - this variant was able to evade immunity provided by COVID 19 vaccines. This is primarily due to the K417N(swapping of lysine and asparagine in position 417) mutation and the E484K(swapping of glutamic acid and lysine in position 484) mutations on the SPIKE protein. The K417N mutation allows the virus to evade the monoclonal antibody treatment, while the E484K mutation is an escape mechanism, allowing it to evade the immune system of the host. 





Moving out of Africa, the next variant spanned two continents and was the most infectious yet. P.1 variant originated in Brazil and soon spread across the Pacific to the island of Japan. The rapid spread of this variant soon propelled Brazil to the top of a very grim leaderboard: the most COVID cases in a day. This variant contains 3 key mutations that allow it to be so infective. As discussed before, the N501Y mutation allows the virus to bond easier with the ACE2 receptor on the human respiratory cells, and the E484K mutation acts as a way for the virus to evade human immune systems. However, this virus also carries a crucial mutation, known as K417T, which allows it to be very infective. In fact, this variant is over 150% more infective than the Wuhan strain, meaning that it is the most infective variant. Additionally, another strain of this variant, the P.2 variant, is 80% more lethal than the P.1 variant, and the P.1 variant is even able to cause severe illness in younger people, irrespective of age. These variants have proved to be some of the most dangerous in the world, but there is one more that has been proven to cause mass destruction, and the most commonly known one today: the B.1.617 lineage.





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The B.1.617 lineage of variants is some of the most talked-about today, due to the area in which it originated: India. This variant has made India a hotspot for COVID 19 infection due to poor infrastructure and only a fraction of the population being fully vaccinated. This combined with the 1.3 billion people living in very densely populated areas leads to a recipe for disaster. This variant also carries some genetic mutations on the SPIKE protein. The P681R mutation allows for better binding to the ACE2 receptor, and this is a mutation-specific to the B.1.617 lineage. This variant also contains the E484K mutation and L524R mutations. Both of these are common in other variants, hence the common name Double Mutant. This variant is over 120% more infective than the original Wuhan variant and is a variant of concern all over the world. Additionally, another even more infective strain has developed in the state of Andhra Pradesh, known as B.1.617.2. This strain contains a different mutation on the SPIKE protein, T478K, which allows for even better infectivity rates.




The variants of COVID 19 have caused mass destruction in the world, infecting millions and killing tens of thousands of people every day. The UK variant caused the entire country to enter a lockdown state, and the South African variant shut down the economy of one of the most populous countries in Africa. The Brazilian variants propelled it to the top of the world in daily cases, and the Indian variant is currently wreaking havoc on the country, having infected over 25 million people. All of these variants are caused by unique mutations like N501Y and E484K. As a scientific community, we need to be prepared and learn how to adequately treat these mutations along with learning how COVID 19 mutates to gain a better understanding of the virus. Although we can see the light at the end of the tunnel, we must be cautious; otherwise, the world will go back to the perilous state it was in a year ago.





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