This is part 87 of our coronavirus FAQ. Click here to read other installments: #Coronavirus the facts. Find the latest information and answers from experts on everything COVID-19.
Differences from original virus
A virus is unable to multiply on its own. The coronavirus enters the living cell of a human and replicates using sources in the cell. During this process, there are occasionally small mistakes with the RNA, the substance which carries the virus’s genetic information. The mistake is what is known as a mutation.
Studies have found that small mutations occur in the virus at a pace of one every two weeks when infections are ongoing. Most of these mutations are small and inconsequential. But sometimes, they affect a crucial part of the gene information and lead to big changes in the characteristics of the virus.
The three strains labeled as “variants of concern” (VOC) by the WHO were detected in the UK, South Africa and Brazil.
The common point linking the three is that a mutation has affected the virus’s spike protein, the part that allows it to infect human cells. Experts believe the mutation has made the variants more infectious than the original virus.
Types of variants
The variants are classified based on what parts of the gene information are affected by the mutation.
The strain was confirmed in the UK in December of last year and has since spread around the world. It is most common in the UK and its official name is “VOC-202012/01.”
The variant has a mutation called N501Y that affects the virus’s spike proteins. The lettering refers to the asparagine (N) in the protein’s No. 501 amino acids that is replaced by tyrosine (Y).
South Africa variant
The strain identified in South Africa is known as “501Y.V2”. It also has the N501Y mutation found in the UK variant.
But this strain also has another mutation known as E484K. The lettering refers to the glutamine (E) in the spike protein’s No. 484 amino acid that is replaced by lysine (K).
This strain was first identified in January during an airport quarantine check in Japan of passengers arriving from Brazil. It has both the N501Y and E484K mutations, like the South Africa variant.
These three strains are worrying health officials because the mutations could make them more infectious than the original virus, and reduce the effectiveness of vaccines. But other variants have emerged around the world.
Strains with the N501Y mutation have been found in the Philippines, while those with the E484K mutation have been identified in Japan. Additional variants have been found in the US. As more people get infected, more strains could emerge.
This information is accurate as of April 21, 2021.