Covid-19: Now, a new variant, Lambda, found in 29 countries

Virendra Pandit

New Delhi: The coronavirus that sparked the Covid-19 pandemic since 2020 is fast mutating into variants and sub-variants. With the World Health Organization (WHO) identifying these mutants with Greek alphabets, the ancient language has suddenly attracted popular attention.

The Greek alphabet has 24 letters, from Alpha to Omega.

After Alpha, Beta, Gamma, and Delta, a new variant of SARS-CoV-2—called Lambda–has emerged and been reported in 29 countries.

The WHO has labeled Lambda as a variant of interest (VoI). It is being tracked by health organizations the world over but is yet to be proven as a serious health hazard.

The WHO’s latest weekly bulletin said the new variant, initially detected in Peru in August 2020, has since been reported in 29 countries, mostly in Latin American nations like Argentina and Chile.

“On 14 June 2021, a variant assigned to Pango lineage C.37, GISAID clade GR/452Q.V1, NextStrain clade 20D, was designated as a global VOI, and assigned the WHO label Lambda,” the bulletin read.

Of all the coronavirus cases reported in Peru until April 2021, 81 percent were found coming from the Lambda variant, WHO said, adding that 32 percent of submitted sequences in the last 60 days in Chile are also of this variant, media reported on Saturday.

The global health watchdog said the Lambda variant was being monitored “as an alert for an extended period”, and upon more information and updated assessments, is now considered as “meeting the VOI working definition based upon evidence of continued emergence and suspected phenotypic implications”.

Lambda has been associated with “substantive rates of community transmission“ in multiple countries, with rising prevalence over time concurrent with increased Covid-19 incidence, the watchdog said.

“The earliest sequenced samples were reported from Peru in August 2020. As of 15 June 2021, over 1730 sequences have been uploaded to GISAID from 29 countries/territories/areas in five WHO regions.”

The WHO said Lambda variant’s “elevated prevalence” has been noted particularly in South American countries such as Chile (31 percent overall prevalence among submitted sequences 7 since first detected in this location to date), Peru (9 percent), Ecuador (8 percent), and Argentina (3 percent).

Peru has reported that 81 percent of Covid-19 cases sequenced since April 2021 were associated with Lambda, WHO said, adding that Argentina reported increasing prevalence of Lambda since the third week of February 2021 and that between April 2 and May 19, the variant accounted for 37 percent of the Covid-19 cases sequenced, media reported.

Prevalence of Lambda variant has increased over time in Chile, accounting for 32 percent of sequenced cases reported in the last 60 days “co-circulating at similar rates to variant Gamma (33 percent), but outcompeting variant Alpha (4 percent) over the same period”.

The WHO said the Lambda variant “carries a number of mutations with suspected phenotypic implications, such as a potential increased transmissibility or possible increased resistance to neutralizing antibodies.”

“It is characterized by mutations in the spike protein, including G75V, T76I, del247/253, L452Q, F490S, D614G and T859N,” WHO said.

The WHO bulletin, however, also added that there is currently “limited evidence” on the full extent of the impact associated with these genomic changes. It noted that ‘robust studies into the phenotypic impacts are needed to better understand the impact on countermeasures and to control the spread’.