Browsing by Author "Salinas, Erick"

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    Induction of SARS-CoV-2 neutralizing antibodies by CoronaVac and BNT162b2 vaccines in naive and previously infected individuals
    (2022) Muena, Nicolas A.; Garcia-Salum, Tamara; Pardo-Roa, Catalina; Jose Avendano, Maria; Serrano, Eileen F.; Levican, Jorge; Almonacid, Leonardo, I; Valenzuela, Gonzalo; Poblete, Estefany; Strohmeier, Shirin; Salinas, Erick; Munoz, Andres; Haslwanter, Denise; Dieterle, Maria Eugenia; Jangra, Rohit K.; Chandran, Kartik; Gonzalez, Claudia; Riquelme, Arnoldo; Krammer, Florian; Tischler, Nicole D.; Medina, Rafael A.
    Interpretation The decay of nAbs titres in previously infected individuals over time indicates that vaccination is needed to boost humoral memory responses. Immunization of naydve individuals with two doses of CoronaVac induced nAbs titres that were significantly lower to that of convalescent patients, and similar to vaccination with one dose of BTN162b2. The real life effectiveness for CoronaVac in Chile was higher than estimated; indicating that lower titres and additional cellular immune responses induced by CoronaVac might afford protection in a highly immunized population. Nevertheless, the lower nAb titre induced by two doses of CoronaVac as compared to the BTN162b2 vaccine in naydve individuals, highlights the need of booster immunizations over time to maintain protec-tive levels of antibody, particularly with the emergence of new SARS-CoV-2 variants. Funding FONDECYT 1161971, 1212023, 1181799, FONDECYT Postdoctorado 3190706 and 3190648, ANID Becas/ Doctorado Nacional 21212258, PIA ACT 1408, CONICYT REDES180170, Centro Ciencia & Vida, FB210008, Finan-ciamiento Basal para Centros Cient?ficos y Tecnol?ogicos de Excelencia grants from the Agencia Nacional de Inves-tigaci?on y Desarrollo (ANID) of Chile; NIH-NIAD grants U19AI135972, R01AI132633 and contracts HHSN272201400008C and 75N93019C00051; the JPB Foundation, the Open Philanthropy Project grant 2020-215611 (5384); and by anonymous donors. The funders had no role in study design, data collection and analysis, deci-sion to publish, or preparation of the manuscript. Copyright (c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
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    Viral shedding dynamics reveals sputum as a reliable and cost-saving specimen for SARS-CoV-2 diagnosis within the first 10 days since symptom onset: A prospective cohort study
    (2020) Levican, Jorge; Almonacid, Leonardo I.; Valenzuela, Gonzalo; García-Salum, Tamara; Rojas, Luis; Serrano, Eileen; Pardo-Roa, Catalina; Salinas, Erick; Avendaño, María José; Perazzo, Fabiola; Díaz, Luis Antonio; Valderrama, Sebastián; Ortega, Marcos; Toro, Adriana; Montecinos, Viviana; Riquelme, Arnoldo; Medina, Rafael A.
    Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome virus (SARS-CoV-2) is challenging global public health, due to an increasing demand for testing and the shortage of diagnostic supplies. Nasopharyngeal swab (NPS) is considered the optimal sample for SARS-CoV2 diagnosis and sputum (SPT) has been proposed as an economic alternative. However, the temporal concordance of diagnosis in NPS and SPT has not been addressed. Methods: Through a longitudinal study we compared the shedding dynamics of SARS-CoV-2 RNA evaluated by RT-qPCR in serially collected SPT and NPS obtained from 82 ambulatory and hospitalized patients during acute infection and convalescence. The concordance during the follow-up and cost analysis between both collected specimens was evaluated. Findings: We analyzed 379 samples, 177 NPS and 202 SPT. The highest proportion of positive samples was detected within the first 15 days after the symptoms onset. The median time of positivity was higher for NPS (median= 25 days) than SPT (median= 21 days). There was no significant difference in the median RT-qPCR CT values between both sample types. The temporal categorization of matched-paired samples indicated substantial correlation (r=0·6023) and substantial agreement (87·23%) during the first ten days since symptoms onset (kappa = 0·697). A cost analysis demonstrated a significant saving when the SPT specimen was used. Interpretation: Sputum is a feasible and cost-saving alternative to NPS, providing an equivalent value for the detection and follow-up of SARS-CoV-2 RNA.