What You Should Know About the Lambda Variant

The massive spread of SARS-CoV-2  Lambda (C.37 lineage) in South American countries has contributed to its recent  declaration as global VOI by the WHO (Figure 1). Since its initial identification  in Nov 2020, the Lambda variant has expanded rapidly in Peru, Chile and Argentina  in the presence of hundreds of circulating lineages, and appears to have  replaced the highly transmissible Alpha variant (B.1.1.7 lineage) in some  densely populated regions.

Fig 1. Epidemic dynamics of the Lambda variant in three South  American countries1.

Characterized by a unique 7-amino acid  deletion (S:Δ247-253,  located at the N-terminal domain) and six nonsynonymous mutations in the spike  gene (G75V, T76I, L452Q, F490S, D614G, T859N) (Figure 2) 2, 3, the SARS-CoV-2 Lambda variant display a novel mutation pattern  that requires close investigation2.

 Fig 2. Mutations identified on the Lambda  variant3.

The Lambda variant is associated with  higher risk of developing severe symptoms and substantial reduction in  neutralizing activity of monoclonal antibodies, convalescent and vaccine sera. Researchers  at NYU have demonstrated with pseudovirus assays that lambda spike caused a  3-fold increase in ACE2 binding, which underlies its high infectivity. In the  same study, the lambda spike showed 3.3-fold, 3-fold, and 2.3-fold resistance  to neutralization by convalescent sera, Pfizer BNT162b2 and Moderna mRNA-1273  vaccinee serum, respectively, as compared to neutralization of virus with the  parental D614G spike (Figure 3)⁴.
 

   Fig 3. The Lambda spike shows partial resistance to neutralization by  convalescent sera and vaccine-elicited sera (Pfizer BNT162b2 and Moderna  mRNA-1273).

Preliminary  studies show that the increased infectivity and resistance of Lambda were likely  attributed to the L452Q and F490S mutations on RBD as well as the large  deletions on NTD “supersite”. Further research is needed to determine how the mutations  specifically impact the dynamics, severity and immune breakthrough of this new  variant of interest.

In order to  support the fight against SARS-CoV-2 variants, ACROBiosystems is accelerating  the development of recombinant S and N antigens with the Lambda mutations. The  Lambda spike trimer protein was verified by SDS-PAGE and SEC-MALS with high  purity (more than 90%).

Lambda variants related product list

Assay Data

The purity  of SARS-CoV-2 Spike Trimer, His Tag (Cat. No. SPN-C52Hs) is more than 90% and  the molecular weight of this protein is around 540-595 kDa verified by  SEC-MALS.

Reference

• 
  

• Izumi Kimura, Yusuke Kosugi,  Jiaqi Wu, et al. SARS-CoV-2 Lambda variant exhibits higher infectivity and  immune resistance. bioRxiv 2021.07.28.454085; doi: https://doi.org/10.1101/2021.07.28.454085.

• Pedro E. Romero, Alejandra  Dávila-Barclay, Guillermo Salvatierra, et al. The Emergence of SARS-CoV-2  Variant Lambda (C.37) in South America. medRxiv 2021.06.26.21259487; doi: https://doi.org/10.1101/2021.06.26.21259487

• https://covdb.stanford.edu/page/mutation-viewer/#lambda

• Takuya Tada, Hao Zhou, Belinda  M. et al. SARS-CoV-2 Lambda Variant Remains Susceptible to Neutralization by  mRNA Vaccine-elicited Antibodies and Convalescent Serum. bioRxiv  2021.07.02.450959; doi: https://doi.org/10.1101/2021.07.02.450959