The outbreak of the novel coronavirus has changed the entire lifestyle of people. After claiming as much as 350,000 lives, the novel coronavirus is reportedly mutating. This mutation has put the researchers in a precarious position. During the first few months of the outbreak, biologists were closing in on identifying a proper diagnosis. However, they had to reconsider their findings to fit the newly formed strain of this virus. As of now, biologists have confirmed two major strains of this virus.
In addition to that, they have grouped the virus into two supertypes, in accordance with the geological location. Now, the question that the researchers must ask themselves to stem this outbreak is, whether this mutation is making the virus more contagious. But before we get to that, let us know which virus causes the coronavirus disease. Moreover, it is essential to know how this virus mutates. So that we could get a gist as to how contagious the new version of coronavirus is.
SARS-Cov-2: Severe Acute Respiratory Syndrome-Coronavirus-2
SARS-Cov-2 is the virus that causes the coronavirus disease. This virus is a successor to SARS-Cov-1, which affected the parts of Asia in 2003. As of now, there is no certainty over how this virus spread to humans. It is believed that either Horseshoe Bats or Pangolins are the natural reservoirs of this disease. Wherein, the SARS shares 96% of its genomes with the bats’ coronavirus and 92% with the Pangolins’.
Although the bats were considered to be the primary hosts, the biologists believe the transmission of this disease to humans was through an intermediate host. This intermediate host can either be Pangolins or Civets. This virus affects different people in different ways. Hence, it is hard to specifically claim their symptoms. However, some of its common symptoms include Fever, dry cough and tiredness. As of now, there are no specific vaccines for treatment.
The science behind SARS-Cov-2’s mutation
Taxonomically, SARS-Cov-2 is a positive-sense single-stranded RNA virus. It has a single linear RNA segment and is packed inside a protein shell. Generally, RNA viruses tend to mutate more often than DNA viruses. Hence, SARS-Cov-2 are prone to mutations. Moreover, the biologists saw this coming, even before the virus made its first copy.
However, the virus can’t replicate itself. It hacks into another organism cell and uses their machinery to make new copies. Firstly, the virus would contract with a ribosome. Then, this ribosome reads the blueprint and starts building new versions. The ribosome reads three nucleic acids at a time. This combination of these three acids constitutes an amino acid. Stringing these amino acids together yield proteins.
Occasionally, wrong nucleic acid will get added to this chain. This can sometimes lead to changes down the line. For instance, initially, the combination of nucleic acids might yield glutamine. But the addition of wrong nucleic acid might result in different amino acids, say, proline. Each amino acid is responsible for the characteristics of the virus. Hence this change would reflect on the virus’ characteristics. It will change the shape of the virus, the organs it affects, and most importantly, its transmission rate.
To put it into perspective, these mutations are akin to typos in the text. When the virus makes mistakes in its genome while copying itself, it creates a typo. These “typos” accumulate and carry over to future copies. Just like how typos change the meaning of a text, mutations change the characteristics of the virus.
L & S Type Strains
Scientists are currently tracking down the different versions of the coronavirus. Recently, a study revealed that the virus strain found in humans is different from what they observed in animals. In addition to that, there are different types of viruses that contract humans. This is a result of mutation. As of now, scientists have ascertained to two strains: L & S type. While one is more harmful, the other one is less prevalent. Studies concluded that the S type strain was seen more frequently in the early stages of the outbreak. Meaning, it could have mutated from S type. Moreover, the aggressive strain, L type, infected 70% of people. Currently, the frequency of this strain has dropped.
The two identified supertypes of coronavirus based on geographical location
It is important to group the virus on the basis of its geographical location. After originating from the Wuhan district, the virus was prevalent within China for the first 57 days. Towards the end of January, the virus made its way to 25 countries. Before February, 73.5% of total registered cases came from 10 East-Asian countries. Things settled down for a bit, in the month of February. Surprisingly, there were only two isolated infections in the first 3 weeks of February.
After this “Global pause”, Europe saw a significant surge in the number of cases. It went from 6% of global cases to 56%. It was this “European explosion” that made this disease a global pandemic. Hence the two supertypes of coronavirus are “East Asian” and “European”. Although the scientists have a limited amount of data with them, they believe as if this shift in geography is one among the reasons for this mutation. Because the virus found in China is different from what was observed in Italy.
Will the virus mutate further?
The drastic changes in the number of cases tell us that the virus has indeed mutated, and is capable of mutating further. SARS-Cov-2 is one of the rare kinds of RNA Viruses that has a proofreading mechanism. Meaning, its mutation rate decreases periodically. Despite that, the data on SARS-Cov-2 show that it mutates at an average of about two mutations per month. Scientists are tracking the virus and sequencing them by reading its genetic code.
Tracking virus genomes gives clarity over how and where the virus is spreading. This helped us in identifying the strain that infected the majority of the U.S patients. To say that the mutation is no threat to the outbreak would be quite far-fetched. Recently, a study concluded that when the virus mutates it could potentially spread faster. According to Angela Rassmussen, a virologist, “We have seen in other virus epidemics, such as the Ebola epidemic, that there are these mutations that seem to persist and become the dominant form of the virus”
Is there a need for different treatment methods for a different?
As of now, the biologists are able to predict the changes that the virus might undergo. Hence, there won’t be a need for a different diagnosis. In addition to that, even if the biologists are taking a vaccine-approach, the vaccine would target multiple sites on the virus. Hence it is unlikely for a few random mutations to make the virus unresponsive. Then again, the studies were conducted with a limited database. Now that the virus has been declared an “endemic”, it is important to abide by the social distancing norms.