Lambda Variant Identified In Texas As Delta Sweeps Across The US

A hospital in Texas has just confirmed its first case of the coronavirus Lambda variant. Houston Methodist Hospital reported the case this week as hospitals in Greater Houston predict a fourth wave of Covid-19 with the Delta variant sweeping across the region.

According to USA Today, more than 80% of sequenced cases in the country have been identified as the Lambda variant. The World Health Organization (WHO) said rising cases of the Lambda variant have been reported from Argentina and Chile, and have been identified in 29 countries.

Scientists at the Medical University of South Carolina announced they spotted the Lambda variant in a virus sample that was taken in April. WHO classified the new strain as a variant of interest while further studies track its transmissibility since the first detection in Peru in December 2020.

A “variant of interest” means the strain goes through genetic changes that affect the usual characteristics of the virus. The changes are what triggers a significant community spread of Covid-19.

Data repository tracking coronavirus variants show that less than 700 cases of the Lambda variant have been sequenced in the United States out of 34 million Covid-19 cases reported to date. Genome sequencing allows scientists and researchers to identify as well as characterize emerging variants.

Shared data from the GISAID Initiative shows that fewer than 1% of US cases in recent weeks have been identified as the Lambda variant.

Dr. S. Wesley Long, medical director of diagnostic biology at Houston Methodist, said that while this variant of interest has mutations similar to other variants of concern, it does not appear to have the same rapid transmissibility as the Delta variant.

Mutations that have been found in the Lambda variant are similar to the Alpha and Gamma variant. Although the Gamma variant did not take hold in the US, Long said it has more concerning mutations compared to the Lambda variant.

The new strain spread in parts of South America largely because of a "founder effect”. A few cases caused the spread within a densely populated and geographically restricted area and over time it became the primary driver for the spread locally.

The spread of the Gamma variant which was first detected in Brazil can be similarly compared to the Lambda variant, Long added.

Dr. Abhijit Duggal, director for critical care research of the medical ICU at the Cleveland Clinic said more data needs to be studied to find out the efficacy of available vaccines against the Lambda variant but said there is no reason to believe it will be ineffective. Although current studies suggest that vaccines used in the US are highly effective against multiple variants of the coronavirus, its efficacy may be lower against the Lambda, he added.

Meanwhile, The Centers for Disease Control and Prevention (CDC) who keeps its own list of variants of concern and interest, said that Lambda is not on its list as being a variant of interest, concern or high consequence.