As India fights the second wave of the COVID-19 virus, new strains have surfaced. While there are triple mutant strains that are being analysed, a new strain — B.1.618 — has been identified in West Bengal as well. This is being thought of as the second variant of the double mutant strain — B.1.617. It has been identified and made public through a tweet from a researcher at the Council of Scientific and Industrial Research’s Institute of Genomics and Integrative Biology, Vinod Scaria. What is B.1.618 and why is the Coronavirus mutating so much? Should we be worried?
How is the B.1.618 different?
Scaria said that the new variant is an immune escape variant — which means that the new variant has the ability to resist antibodies that have developed in our bodies due to exposure to the virus in any for the past year. “B.1.618 – a new lineage of SARS-CoV-2 predominantly found in India and characterized by a distinct set of genetic variants including E484K, a major immune escape variant,” tweeted Scaria. “There are many unknowns for this lineage at this moment including its capability to cause reinfections as well as vaccine breakthrough infections. Additional experimental data is also required to assess the efficacy of vaccines against this variant,” he added.
Even though the term “viral mutation” sounds ominous, it is important for us to understand that a lot of these mutations are generally minor, and often don’t have any major impact on how fast the virus spreads or how deadly it might be. it is very much possible that the mutations might even make the virus less infectious. Most of what we know about virus mutation gives the new strains the ability to bypass the effects of the antibodies comes from our observation of the flu virus. This has also helped us keep updating the flu vaccines to fight the new strains that come up. Flu viruses mutate in two ways, mostly, antigenic shift and antigenic drift.
Why is the Coronavirus mutating? What is virus mutation?
We need to understand why a virus mutates. When a living organism replicates, the genes go through changes based on the climate, the surroundings and a hoard of other things. While it is replicating, the virus sometimes faces errors in copying the genes — the gene is not copied properly or a different variation happens. This changes the proteins and antigens on the virus’ surface over a period of time. Now, our immune system knows a virus from its antigens and the antibodies in our body fight them on the basis of these antigens. A series of genetic mutations over a period of time “drifts” the antigens — the surface of the new variant of the same virus starts to look different than what the original virus looked like. When the virus has drifted enough, the vaccines that are meant to fight the old strains of the virus and provide immunity to us no longer work. This makes even a vaccinated person vulnerable to the new strain.
Do we need new vaccines?
But the Coronaviruses have only mutated till now. There has not been any antigenic drift. This means that the researchers do not have to alter the vaccine as of yet. But that is not assurance enough. The COVID-19 virus is a flu virus and it is not a stretch to believe that it will start mutating and behaving much like an influenza virus at some point. This is why the experts have said that the researchers should be ready to make changes to the vaccine if needed.
What’s happening in West Bengal?
This is not the first time that the B.1.618 virus has been identified in West Bengal. It was first found on October 10 last year. Then why is it in the news now? What is double mutation? Because the cases of people being affected by the B.1.618 has increased over the past few months and now the state is seeing a surge in the cases of B.1.618. “More focused epidemiological investigations would address these questions,” Scaria said. “Initial sequences in the B.1.618 lineage were found in West Bengal, India. Members of this lineage are also found in other parts of the world but do not have the full complement of variants as found in India…The proportions of B.1.618 has been growing significantly in the recent months in the state of West Bengal,” added the researcher.
B.1.618 – a new lineage of SARS-CoV-2 predominnatly found in India and characterized by a distinct set of genetic variants including E484K , a major immune escape variant. pic.twitter.com/dtfQJp2S2B
— Vinod Scaria (@vinodscaria) April 20, 2021
But he also accepted that there is no evidence to prove that this strain is responsible for the rapid surge in Bengal. “There are many unknowns for this lineage at this moment including its capability to cause reinfections as well as vaccine breakthrough infections. Additional experimental data is also required to assess the efficacy of vaccines against this variant. At this moment, there is no conclusive evidence that the lineage drives the epidemic in West Bengal, apart from the fact that the nos and proportions have been significantly increasing in recent months. More focused epidemiological investigations would address these questions,” he said.
Reply to a question on the same Twitter thread, Scaria said, “Unfortunately most manufacturers do not reveal the primer/probe sequences used in the RT-PCR kits marketed in India not is there a compiled resource to make such assessments.”