Friday, May 27, 2022

Explained: Why Lambda Variant Is Critical Even While World Is Struggling To Deal With Delta

Kappa is a sub-lineage of B.1.617 variant, first reported in Maharashtra, India, in October 2020.

Explained: Why Lambda Variant Is Critical Even While World Is Struggling To Deal With Delta
The sub-lineage B.1.617.1 is now known as Kappa while B.1.617.2 is known as the Delta variant. File Photo

2021 has been in the headlines more for variants of Covid-19. Delta variant has become famous because of the second wave being predominantly caused by it. Delta plus also created ripples. Since last week, we have been hearing about the kappa variant being detected in an Indian state and lambda variant detected in Peru being labelled as a variant of interest by WHO. So, it’s very important to understand what is a variant and how dangerous it could be based on the properties

Virus keeps on changing and if there are changes in genetic sequence, it is known as mutations. Most of the mutations are insignificant and do not alter the characteristics of the virus. However, of the many such mutations, a few may affect the virus’s ability (a) to spread or transmit; (b) to cause severe disease; or (c) its performance against vaccines, therapies, diagnostic tools, and other public health and social measures. If any such mutation happens in SARS-CoV-2 with properties that are under investigation and not yet scientifically proven, they are called Variants of Interest or VOI; and when the properties are proven, they have termed Variants of Concern (VOC). This process of designating a variant VOI or VOC is dynamic and based on continuous risk assessment. A variant can be upgraded or downgraded to different categories based on the most recent evidence and risk assessment. 


Kappa is not a new variant and is already designated a Variant of Interest since April 2021. However, it was back in the news in the second week of July, when two cases were reported from the genomic sequencing data of an Indian state.

Kappa is a sub-lineage of B.1.617 variant, first reported in Maharashtra, India, in October 2020. This variant was subsequently identified as a triple mutant by the Indian government in late March 2021, as it had three mutations of interest.


The Delta variant, first discovered in India, has been attributed as the driver behind the country’s devastating second covid wave, which saw cases and deaths rise exponentially. According to a study, vaccines are also eight times less effective against the variant, as compared to the original strain found in Wuhan, China. The sub-lineage B.1.617.1 is now known as Kappa while B.1.617.2 is known as the Delta variant. The Delta variant is responsible for the emergence of the second wave in India; it has been found in nearly 100 countries and is a global VOC. 

In simple terms, Kappa is a sibling of Delta. However, as in a family, siblings could be very different from each other, and that exactly is the case with Kappa and Delta. While the Delta variant has higher transmissibility, documented immune escape, and breakthrough infections, none of these properties have been documented for the Kappa variant, so far. Kappa variant is not a major concern as of now.

Delta Plus

The new Delta plus variant has been formed due to a mutation in the Delta or B.1.617.2 variant, first identified in India and one of the drivers of the deadly second wave. Some cases of the ‘Delta plus’ variant of Covid-19, considered highly infectious, have been reported in Maharashtra threatening to massively dent the state’s fight against the virus as experts warn that this variant may trigger a third wave of the pandemic in the state.

It has been detected in nine countries, including UK, Portugal, Switzerland, Poland, Japan, Nepal,


Lambda variant (C.37) is in the news because it is the seventh and the latest VOI to get designated by the WHO on June 14, 2021. The variant was first reported from Peru, possibly as early as December 2020. At present, it is the most dominant variant in Peru (around 80 per cent of all cases in the country) and Chile and is widely circulating in South America. By June 2021, it had been reported in around 25 countries, including in the UK, France, Germany, Italy, and Australia. However, the number of COVID cases as a result of this variant outside South America remains small. No case of Lambda variant has yet been reported from India or neighbouring countries


The designation of a variant as VOI or VOC is an important part of the global response to the pandemic. However, no matter which variant it is, there is no change in the recommended measures to prevent SARS-CoV-2. Most of the currently licensed vaccines are effective against these variants may be less in some however it still protects against severe Infection. Therefore, we must get vaccinated. Kappa is not a cause of immediate concern and there has not been any documented change in the properties of the virus; therefore, you don’t need to panic. Lambda variant has not been reported from India; however, the Indian government should keep an eye out by stepping up genomic sequencing.

Epidemiologically, there is a real possibility of a third wave in India and it is possible that if a new variant emerges, the third wave could arrive early delta plus could be the trigger behind the third wave as far as India is concerned at the citizen level, we must keep following COVID- appropriate behaviour, which includes wearing a face mask, maintaining physical distancing, washing hands and getting vaccinated. That’s how we fight the virus and reduce the impact of any subsequent wave, as and when that happens.

(Dr Sulaiman Ladhani, Consulting Chest Physician, MD Chest and Tuberculosis, Masina Hospital)