New Delhi | Jagran News Desk: Even as India continues to reel under the unprecedented second wave of COVID-19, the discovery of a new triple mutant strain has posed a fresh challenge in the country’s battle against the deadly virus.

After the double mutation, cases of triple mutation - where three different COVID-19 strains combine to form a new variant - have been detected in parts of the country. As per reports, states like Maharashtra, Delhi and West Bengal are believed to have cases driven by the triple mutant.

Here is what you should know about the triple mutation variant of COVID-19:

What is triple mutation variant?

The B.1.617 variant, first detected in Maharashtra, contains mutations from two separate virus variants -- E484Q and L452R. The third mutation evolved from the double mutation where three different COVID strains combined to form a new variant - B.1.618.

Both the E484Q mutation (reported in both UK and South African variants) and L452R mutation (found in the California strain) have been associated with much greater binding and antibody escape capabilities.

Vinod Scaria, a scientist at the Council of Scientific and Industrial Research’s Institute of Genomic and Integrative Biology (CSIR-IGIB) in New Delhi, explained in a Twitter thread that the new strain is characterised by the deletion of two amino acids (H146del and Y145del), as well as possessing E484K and D614G variants in spike protein. All this, according to him, helps in increased infectivity capabilities.

Is the third mutation variant more dangerous?

Scaria said that the proportions of B.1.618 has been growing significantly in the recent months in the state of West Bengal, along with double variant B.1.617.

The extent of infection caused by the third mutation and how deadly it is will be known only from more studies. For now, only 10 labs across India are involved in virus genome studies.

"This is a more transmissible variant. It is making lots of people sick very quickly. We have to keep tweaking vaccines. For that we need to understand the disease. But we need sequencing on war footing," NDTV quoted Madhukar Pai, professor of epidemiology at McGill University, as saying.

Why and how virus mutates?

Viruses mutate all the time, as part of evolutionary biology. Some mutations weaken the virus while others make it stronger, enabling it to proliferate faster or cause more infections.

"As the virus spreads, it gets more opportunities to acquire mutations and evolve at a faster rate. This is a natural aspect of virus life-cycle but it is very important that we track these changes (virus surveillance) and follow the important viral characteristics associated with these mutations," Dr Veena P. Menon, Faculty-In-Charge, Clinical Virology Laboratory, Amrita Institute of Medical Sciences, Kochi, told IANS.

While the SARS-CoV2, causing the Covid-19 infections, has evolved at a much slower rate compared to Influenza or HIV viruses but as the number of infections rises, we are observing a rapid emergence of numerous viral variants.

With the increase in the number of infections and spread, there are more opportunities for the virus to mutate.

"As the infections are increasing at an alarming rate, there is a very high likelihood that we will encounter more virus variants in our population. Some of these variants get selected for faster transmissibility (spread) or 'increased severity' (more pathogenic) and also "immune (vaccine) escape", Menon explained.

The evidence so far suggests that none of the important virus variants are associated with increased severity. However, an increased transmissibility is associated with the UK variant (lineage B1.1.7) while the Brazilian and South African variants exhibit ability to escape vaccine-induced immunity.

"Mutation in the respiratory virus is a natural process. This process is augmented in situations of high spread and presence of vaccinated people in the community. We will see more variants in India in future too," Dr Harshal R. Salve, Associate Professor at Centre for Community Medicine, AIIMS New Delhi, told IANS.

Posted By: Abhinav Gupta