Torres C, Mojsiejczuk L, Acuña D, Alexay S, Amadio A, Aulicino P, Debat H, Fay F, Fernández F, Giri AA, Goya S, König G, Lucero H, Nabaes Jodar M, Pianciola L, Sfalcin JA, Acevedo RM, Bengoa Luoni S, Bolatti EM, Brusés B, Cacciabue M, Casal PE, Cerri A, Chouhy D, Dus Santos MJ, Eberhardt MF, Fernandez A, Fernández PDC, Fernández Do Porto D, Formichelli L, Gismondi MI, Irazoqui M, Campos ML, Lusso S, Marquez N, Muñoz M, Mussin J, Natale M, Oria G, Pisano MB, Posner V, Puebla A, Re V, Sosa E, Villanova GV, Zaiat J, Zunino S, Acevedo ME, Acosta J, Alvarez Lopez C, Álvarez ML, Angeleri P, Angelletti A, Arca M, Ayala NA, Barbas G, Bertone A, Bonnet A, Bourlot I, Cabassi V, Castello A, Castro G, Cavatorta AL, Ceriani C, Cimmino C, Cipelli J, Colmeiro M, Cordero A, Cristina C, Di Bella S, Dolcini G, Ercole R, Espasandin Y, Espul C, Falaschi A, Fernandez Moll F, Foussal MD, Gatelli A, Goñi S, Jofré ME, Jaramillo J, Labarta N, Lacaze MA, Larreche R, Leiva V, Levin G, Luczak E, Mandile M, Marino G, Massone C, Mazzeo M, Medina C, Monaco B, Montoto L, Mugna V, Musto A, Nadalich V, Nieto MV, Ojeda G, Piedrabuena AC, Pintos C, Pozzati M, Rahhal M, Rechimont C, Remes Lenicov F, Rompato G, Seery V, Siri L, Spina J, Streitenberger C, Suárez A, Suárez J, Sujansky P, Talia JM, Theaux C, Thomas G, Ticeira M, Tittarelli E, Toro R, Uez O, Zaffanella MB, Ziehm C, Zubieta M, Mistchenko AS, Valinotto L, and Viegas M
SARS-CoV-2 variants with concerning characteristics have emerged since the end of 2020. Surveillance of SARS-CoV-2 variants was performed on a total of 4,851 samples from the capital city and 10 provinces of Argentina, during 51 epidemiological weeks (EWs) that covered the end of the first wave and the ongoing second wave of the COVID-19 pandemic in the country (EW 44/2020 to EW 41/2021). The surveillance strategy was mainly based on Sanger sequencing of a Spike coding region that allows the identification of signature mutations associated with variants. In addition, whole-genome sequences were obtained from 637 samples. The main variants found were Gamma and Lambda, and to a lesser extent, Alpha, Zeta, and Epsilon, and more recently, Delta. Whereas, Gamma dominated in different regions of the country, both Gamma and Lambda prevailed in the most populated area, the metropolitan region of Buenos Aires. The lineages that circulated on the first wave were replaced by emergent variants in a term of a few weeks. At the end of the ongoing second wave, Delta began to be detected, replacing Gamma and Lambda. This scenario is consistent with the Latin American variant landscape, so far characterized by a concurrent increase in Delta circulation and a stabilization in the number of cases. The cost-effective surveillance protocol presented here allowed for a rapid response in a resource-limited setting, added information on the expansion of Lambda in South America, and contributed to the implementation of public health measures to control the disease spread in Argentina., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Torres, Mojsiejczuk, Acuña, Alexay, Amadio, Aulicino, Debat, Fay, Fernández, Giri, Goya, König, Lucero, Nabaes Jodar, Pianciola, Sfalcin, Acevedo, Bengoa Luoni, Bolatti, Brusés, Cacciabue, Casal, Cerri, Chouhy, Dus Santos, Eberhardt, Fernandez, Fernández, Fernández Do Porto, Formichelli, Gismondi, Irazoqui, Campos, Lusso, Marquez, Muñoz, Mussin, Natale, Oria, Pisano, Posner, Puebla, Re, Sosa, Villanova, Zaiat, Zunino, Acevedo, Acosta, Alvarez Lopez, Álvarez, Angeleri, Angelletti, Arca, Ayala, Barbas, Bertone, Bonnet, Bourlot, Cabassi, Castello, Castro, Cavatorta, Ceriani, Cimmino, Cipelli, Colmeiro, Cordero, Cristina, Di Bella, Dolcini, Ercole, Espasandin, Espul, Falaschi, Fernandez Moll, Foussal, Gatelli, Goñi, Jofré, Jaramillo, Labarta, Lacaze, Larreche, Leiva, Levin, Luczak, Mandile, Marino, Massone, Mazzeo, Medina, Monaco, Montoto, Mugna, Musto, Nadalich, Nieto, Ojeda, Piedrabuena, Pintos, Pozzati, Rahhal, Rechimont, Remes Lenicov, Rompato, Seery, Siri, Spina, Streitenberger, Suárez, Suárez, Sujansky, Talia, Theaux, Thomas, Ticeira, Tittarelli, Toro, Uez, Zaffanella, Ziehm, Zubieta, Mistchenko, Valinotto and Viegas.)