Double Mutant: Negligence, bogus information to an unprecedented health crisis

Pratibha Pansari
6 min readMay 2, 2021


Credit: GenomeConnect

Over 7,000 individual mutations of the SARS-CoV-2 virus have been documented in India. Evidence is still inconclusive owing to lack of sequencing infrastructure and power; the experts say the ‘double mutant’ is likely to become the dominant form of the SARS-CoV-2 virus in India and some countries abroad. Human behavior is probably more to blame for the second wave of the COVID-19 pandemic than the new mutants arising around the country.

Mankind is challenged, as it has never been challenged before, to prove its maturity and its mastery — not of nature, but of itself.

What is double mutant?

When the virus mutates, it takes the form of a new strain and creates a distinct identity of its own. Simply put, double mutant means that the two strains of the virus get together and form a new one.

Earlier Genome sequencing of a section of virus samples by the Indian SARS-CoV-2 Consortium on Genomics (INSACOG), revealed the presence of two mutations, E484Q and L452R.

INSACOG, a consortium of 10 labs namely DBT-NIBMG Kalyani, DBT-ILS Bhubaneswar, ICMR-NIV Pune, DBT-NCCS Pune, CSIR-CCMB Hyderabad, DBT-CDFD Hyderabad, DBT-InSTEM/ NCBS Bengaluru, NIMHANS Bengaluru, CSIR-IGIB Delhi, and NCDC Delhi.

This double mutant has been scientifically named as B.1.167.

B.1.617 carries more than a dozen mutations, but is sometimes called a “double mutant” because of two prominent mutations: E484Q and L452R.

Though these mutations have individually been found in several countries, the presence of both these mutations together has been first found in corona virus genomes of India.

As per the repost of AL JAZEERA on 30, April 2021,The World Health Organization (WHO) has designated it as a “variant of interest”, suggesting it may be more infectious than other versions of the virus, cause more severe disease or evade vaccine immunity to a greater degree.

Till now only three global ‘Variants of Concern’ have been identified: the U.K. variant (B.1.1.7), the South African (B.1.351) and the Brazilian (P.1) lineage.

What are ‘mutations’ ‘variants’ and ‘lineages’?

Mutation is an alteration in the genetic material (the genome) of a cell of a living organism or of a virus that is more or less permanent and that can be transmitted to the cell’s or the virus’s descendants.

All viruses mutate as they replicate, as a part of natural processes — a mutation occurs when there is an ‘error’ or change in the RNA sequence of the virus as it replicates. Some viruses mutate faster than others, such as the influenza virus.

Mutations are written down in the form of which nucleotide or amino acid is changing, and at what position in the sequence. For example, the E484Q mutation affects the spike protein of the SARS-CoV-2 virus in a way where the amino acid ‘E’ (glutamic acid) is replaced by the ‘Q’ (glutamine) at the 484th position.

As a virus mutates, it can sometimes retain some mutations while also giving rise to more along the way and retaining those. Multiple mutations that spread persistently give rise to a new ‘variant’ of the virus, such as the India variant or the UK variant, also called ‘lineages’.

What is genome sequencing?

  • It is a testing process to map the entire genetic code of an organism, in this case, the virus.
  • The genetic code of the virus works like its instruction manual.
  • Indian SARS-CoV-2 Consortium on Genomics (INSACOG) is a multi-laboratory, multi-agency, pan-India network to monitor genomic variations in the SARS-CoV-2.
Credit: CSIR — IGIB

How genome sequencing does helps:

  • It allows researcher to generate a rich source of information for tracking pathogen transmission and evolution on both national and international levels.
  • Genetic sequencing also reveals how the virus originated, and to some extent, help predict how it may change in the future
  • It helps in the understanding of how the virus spreads and evolves.
  • Provides confirmation of the virus
  • Source of community outbreaks
  • Diagnostics
  • Vaccines and therapies

Why covid 19 symptoms are testing negative?

RT-PCR tests, considered the gold standard in the diagnosis of Covid-19. The minimum sensitivity (ability to detect positives) demanded by the Indian Council of Medical Research (ICMR) for validating an RT-PCR test is 95%. That means up to 5% false negative results are expected.

The conventional SARS-CoV-2 strain usually colonises the nasopharyngeal region where the body’s immune system counters it and stops it from directly accessing the lungs.

However, the double mutant variant was believed to evade the nasopharyngeal region and colonise the lungs directly. This might be the reason why the sample drawn from the nasopharyngeal region might not have the viral load, resulting in the patient being recorded negative.

Along with that various logistic and technical factors like improper sampling, inappropriate transportation and delay in testing as well as usage of less sensitive reagents and technical incompetency had been responsible for COVID-19 positive patients being reported as negative.

Is there any Triple and Bengal mutation? If yes, is it alarming?

There is so much misinformation and confusion circulating in the media report regarding Triple mutant and Bengal Variant.

Credence must not be given to ‘experts’ peddling pseudoscience and untruths.

Triple mutant and Bengal mutant, both are different variant.

Due to the addition of an additional mutation V382L in the spike of double mutant, it has been dubbed as Triple mutant. This is a sub-lineage of B.1.617. It is found mainly in Maharashtra samples and also a bit in other states.

B.1.618 (Bengal variant) was first sampled in West Bengal late Oct 2020 and it has nothing to do with B.1.617 (Double mutant).

The proportions of B.1.618 (Bengal variant) have been growing significantly in the recent months in the state of West Bengal, India.

The main concern with #B1.618 (Bengal variant) is that it’s found in growing proportions in West Bengal and has the Spike del145–146 as well as E484K, both of which are known immune escape mutations. E484K in particular was seen before in both B.1.351 and P.1 lineages (Variant of concern).

As per the Centre for Disease Control, ’variants of concern’ are those for which ‘there is evidence of an increase in transmissibility, more severe disease (e.g., increased hospitalizations or deaths), significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures.’

All varient are innocnet until proven guilty.

Will vaccines work against double and triple and bengal variant?

It is said by the Dr. Rakesh K Mishra (CCMB Director) that both the vaccines (Covaxin and Covishield) as well and natural immunity gained by the prior infection offers protection from B.1.617 (double mutant) variant of novel coronavirus but the results are based on preliminary study.

However, authentic experimental data is required to assess the efficacy of vaccines against these variant and more focused epidemiological investigations would address such questions.

Not everyone agrees but “it should also be noted that the number of viral sequences analyzed in India [about 100 sequences per day] is much smaller than the number of infected people in India [about 4,00,000 per day].

“Rest of the questions will be answered by above said lines.”

Source: MoHFW guidance document on genome sequencing; NCDC

What we can do?

You may have read may article regarding the Covid-19 appropriate behavior and vaccination but from my point of view our own human side is the ultimate shield for this virus.

If we are the part of mass gathering, freely roaming around the street even after being positive (knowingly), we really need to ask ourselves…Is this what we are doing for our own family?

“We still have not become mature enough to see ourselves as a very tiny part of a vast and incredible universe.”

*Opinions expressed are solely my own and do not express the views or opinions of my employer or organizations associated.