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| Medical workers test people for the coronavrius at a makeshift clinic on the premises of a church in Gwangju, 300 kilometers away from Seoul, in this July 3 photo. Yonhap |
By Bahk Eun-ji
A recent series of infection clusters in the Seoul Metropolitan area have revealed that a particularly contagious strain of the coronavirus, the GH strain, is spreading.
It is reported that the GH strain of the virus is transmitted a lot faster than other types, but how dangerous is it? The Korea Centers for Disease Control and Prevention (KCDC) said it is believed to spread six times faster than other strains of the virus.
What happened?
This strain of COVID-19 virus, which has been spreading not only in Korea but also around the world, has been identified as a genotype of the G group ― G, GR, and GH ― which is believed to have spread faster than the initially identified strains of the virus. The S and V groups were more prevalent in Asia, including China from January to March when the outbreak of the virus first occurred. But Since April, the G group has been most prevalent in the United States and Europe.
According to a new study led by scientists and researchers at Los Alamos National Laboratory early this month, the new strain of the coronavirus has become dominant worldwide and appears to be more contagious than the versions that spread in the early stages of the pandemic.
The research, which was largely based on the genetic sequence of earlier strains, said the new strain first appeared in February in Europe, then traveled fast to the U.S. and has been dominant since the middle of March. It is not only spreading faster, but also making people vulnerable to a second infection, it added.
The quarantine authorities here have also become more vigilant. On July 6, the KCDC said it analyzed the sequence of genomes of a total of 526 patients over the past few weeks and it showed 63.3 percent were infected by the GH strain, 24 percent by the V strain and 6.3 percent by the S strain.
In a recent briefing, KCDC Director Jeong Eun-kyong said the most prevalent strain here at its peak ― when daily cases soared up to three-digit figures in mid-February after a huge cluster was found at the Shincheonji Church of Jesus in Daegu ― was the V strain. However, since first being discovered in Europe, the G, GH and GR strains are said to be the most widespread variants in the world now.
What's the difference between S, V, and G?
The World Health Organization (WHO) classifies the COVID-19 virus into six groups, S, V, L, G, GH, and GR, based on amino acid changes caused by genetic sequencing differences. The coronavirus enters the cells of the human body using a spike (protrusion) protein on the particle surface, and changes occur as the components of the amino acids that make up the spike protein change.
In other words, the alphabetical name classifications are abbreviations of certain amino acids. The KCDC explained that the S strain of the virus, which originated from Wuhan, China, quickly migrated into Korea and mutated into V, and then G after crossing into the U.S. and Europe.
To answer the question why the virus keep mutating, experts said they are "evolving."
"When the virus enters the human body, it replicates. In the process, mutation occurs," said Lee Jae-gap, a professor of infectious disease at the College of Medicine at Hallym University.
However, only certain kinds of mutation can make the virus more dangerous to people. Many researchers also said further study is needed to understand whether these mutations have any functional difference.
"Lab results might not provide the full picture either. Just because something's different in a cell doesn't necessarily mean that it's different when you scale that up to the whole human body, Emma Hodcroft, a molecular epidemiologist at the University of Basel in Switzerland was quoted as saying by Science News, referring to the study published by Los Alamos laboratory. "At the end of the day, you're going to need some animal studies or some really good human data."
Will it affect vaccine development?
The KCDC has administered remdesivir, an experimental drug conventionally used for Ebola, for a number of COVID-19 patients from this month. Many wonder if the mutation of the virus invalidates the vaccine treatment, but experts said there will be no significant impact.
"The spike protein of the virus is the key to whether the vaccine will be working or not. Currently, mutations are not occurring in this area, so there will be no major disruption in the development of the vaccines right now," said Jeon Byung-yul, a professor of CHA University School of Medicine.
"However, it is necessary to keep track of other mutations as they may take place in the future," he said.
