Viruses, Vol. 15, Pages 1382: The Lambda Variant in Argentina: Analyzing the Evolution and Spread of SARS-CoV-2 Lineage C.37

Viruses, Vol. 15, Pages 1382: The Lambda Variant in Argentina: Analyzing the Evolution and Spread of SARS-CoV-2 Lineage C.37

Viruses doi: 10.3390/v15061382

Authors: Mercedes Soledad Nabaes Jodar Carolina Torres Laura Mojsiejczuk Dolores Acuña Laura Elena Valinotto Stephanie Goya Monica Natale Silvina Lusso Sofia Alexay Ariel Amadio Matias Irazoqui Franco Fernandez Maria Elina Acevedo Cristina Alvarez Lopez Andres Angelletti Paula Aulicino Elisa Bolatti Bettina Brusés Marco Cacciahue Ana Cavatorta Agustina Cerri Andres Cordero Humberto Debat Maria Jose Dus Santos Maria Florencia Eberhardt Regina Ercole Carlos Espul Marisa Farber Fabián Fay Ailen Fernandez Florencia Ferrini Laura Formichelli Santiago Ceballos Fernando Gallego Adriana Giri Maria Gismondi Raul Maximiliano Acevedo Ivan Gramundi María Eugenia Ibañez Guido Konig Viviana Leiva Melina Lorenzini Campos Horacio Lucero Nathalie Marquez Melina Mazzeo Alicia Susana Mistchenko Luciana Montoto Marianne Muñoz Victoria Nadalich Cristina Nardi Belén Ortiz Luis Pianciola Carolina Pintos Andrea Puebla Carolina Rastellini Alejandro Ezequiel Rojas Javier Sfalcin Ariel Suarez Clara Theaux Guillermo Thomas Estefania Tittarelli Rosana Toro Vanina Villanova Gretel Wenk Cecilia Ziehm Maria Carla Zimmermann Sebastian Zunino Proyecto PAIS Mariana Viegas

The second wave of COVID-19 occurred in South America in early 2021 and was mainly driven by Gamma and Lambda variants. In this study, we aimed to describe the emergence and local genomic diversity of the SARS-CoV-2 Lambda variant in Argentina, from its initial entry into the country until its detection ceased. Molecular surveillance was conducted on 9356 samples from Argentina between October 2020 and April 2022, and sequencing, phylogenetic, and phylogeographic analyses were performed. Our findings revealed that the Lambda variant was first detected in Argentina in January 2021 and steadily increased in frequency until it peaked in April 2021, with continued detection throughout the year. Phylodynamic analyses showed that at least 18 introductions of the Lambda variant into the country occurred, with nine of them having evidence of onward local transmission. The spatial–-temporal reconstruction showed that Argentine clades were associated with Lambda sequences from Latin America and suggested an initial diversification in the Metropolitan Area of Buenos Aires before spreading to other regions in Argentina. Genetic analyses of genome sequences allowed us to describe the mutational patterns of the Argentine Lambda sequences and detect the emergence of rare mutations in an immunocompromised patient. Our study highlights the importance of genomic surveillance in identifying the introduction and geographical distribution of the SARS-CoV-2 Lambda variant, as well as in monitoring the emergence of mutations that could be involved in the evolutionary leaps that characterize variants of concern.