General information on SARS-CoV-2 RBD of Spike protein, L452Q, F490S – C.37 lineage – Peruvian variant – Lambda variant
Lineage C.37 was designated as a new Variant Under Investigation (VUI-21JUN-01) by Public Health England (PHE) in June 2021. This lineage is believed to have originated in Peru as early as December 2020. Since then, it has spread globally and can currently be found at high prevalence in countries such as Chile, the United States of America, Mexico, Ecuador, and several European countries (UK, Germany, France, among others). Together with Peru, the first two countries observe the greatest rates of prevalence for this lineage.
This lineage was also recently named as Lambda variant by the World Health Organization (WHO). It carries several noteworthy mutations, particularly on the receptor-binding domain (RBD), the main driver of infection of the SARS-CoV-2 virus. The mutations comprise amino acid changes L452Q and F490S. Although data regarding the biological significance of these mutations remains scarce, it is hypothesized they are both associated with an enhanced ability to escape the organism’s neutralizing response. Mutation L452Q has previously been reported in some sequences of SARS-CoV-2 but never among the most prevalent variants of the virus. However, a similar mutation – L452R – has been detected in the variant of concern Delta (India), and in the variants of interest (VOI) Epsilon (Southern California) and Iota (New York). There is strong evidence suggesting that this particular mutation has increased SARS-CoV-2 infectivity and host immune evasion potency. In contrast, mutation F490S appears to derive from the Alpha variant (UK), and it is predicted to further improve the ability to evade the immune system. Early studies revealed this new variant displays a reduced sensitivity to convalescent plasma. However, further studies are necessary to elucidate how this new set of mutations will affect the effectiveness of current vaccines.