Outbreak report of SARS-CoV-2 infection by airborne transmission: Epidemiologic and molecular evidence. / Reporte de un brote de infección por SARS-CoV-2 por transmisión aérea: evidencia epidemiológica y molecular

INTRODUCTION: It has been shown that the transmission of SARS-CoV-2 occurs mainly by air, and the risk of infection is greater in closed spaces. OBJECTIVE: To describe the epidemiology, virology and molecular characterization of a COVID-19 outbreak at a closed vaccination point during the third wave of SARS-CoV-2 in Colombia. MATERIALS AND METHODS: Diagnostic tests, interviews, sampling, cell cultures and viral sequencing were carried out, the latter being molecular characterization and lineage identification. RESULTS: Seven workers were positive for SARS-CoV-2; among these, 3 samples were analyzed, plus an additional sample belonging to the mother of the presumed index case; all samples were identified with lineage B.1.625, with a maximum of 2 nucleotides difference between them. CONCLUSIONS: Variant B.1.625 was identified as the cause of the COVID-19 outbreak, and a co-worker was also identified as the index case. Unexpectedly, attending a vaccination day became a risk factor for acquiring the infection.

Introducción. Se ha demostrado que la transmisión de SARS-CoV-2 se produce principalmente por vía aérea y el riesgo de infección es mayor en espacios cerrados con alta concentración de personas; este último factor se presentó en algunos de los puestos de vacunación de la ciudad de Medellín. Objetivo. Describir la epidemiología, virología y caracterización molecular de un brote de COVID-19 en un punto de vacunación cerrado durante la tercera ola de SARS-CoV-2 en Colombia. Materiales y métodos. Se realizaron test diagnósticos, entrevistas, toma de muestras, aislamiento viral y secuenciación genómica. Con esta última, se hizo la caracterización molecular y se identificó el linaje. Resultados. Siete trabajadores fueron positivos para SARS-CoV-2, y de estos, tres muestras fueron secuenciadas, más una muestra adicional perteneciente a la madre del presunto caso índice. Todas las muestras fueron identificadas con el linaje B.1.625, con un máximo de dos nucleótidos de diferencia entre ellas. Conclusiones. Se identificó la variante B.1.625 como la causante del brote de COVID-19, y también un compañero de trabajo fue identificado como el caso índice. De forma imprevista, asistir a una jornada de vacunación se convirtió en un factor de riesgo para adquirir la infección.

Neutralizing antibody titers to Omicron six months after vaccination with BNT162b2 in Colombia.

The emergence of the Omicron variant has generated concerns about the efficacy of COVID-19 vaccines. We evaluated the serum neutralizing activity of antibodies against the Omicron (lineage BA.1.1) by plaque reduction neutralizing test, as well as its correlation with age and gender, in a Colombian cohort six months after being vaccinated with BNT162b2 (Pfizer/BioNTech). Compared to all other variants analyzed, a significantly lower neutralizing activity (p<0.001) was observed against Omicron. Interestingly, older individuals exhibited lower titers against Omicron than those younger than 40. No statistical differences in neutralizing activity were observed according to gender. Our results showed that two doses of BNT162b2 might not provide robust protection against the Omicron variant over time. It is necessary to consider including changes in the composition of the vaccines to protect against new emerging variants of SARS-CoV-2 and campaigns to implement additional booster vaccinations.

SM-COLSARSPROT: Highly Immunogenic Supramutational Synthetic Peptides Covering the World's Population.

Fifty ~20-amino acid (aa)-long peptides were selected from functionally relevant SARS-CoV-2 S, M, and E proteins for trial B-21 and another 53 common ones, plus some new ones derived from the virus' main genetic variants for complementary trial C-21. Peptide selection was based on tremendous SARS-CoV-2 genetic variability for analysing them concerning vast human immunogenetic polymorphism for developing the first supramutational, Colombian SARS-protection (SM-COLSARSPROT), peptide mixture. Specific physicochemical rules were followed, i.e., aa predilection for polyproline type II left-handed (PPIIL) formation, replacing ß-branched, aromatic aa, short-chain backbone H-bond-forming residues, π-π interactions (n→π* and π-CH), aa interaction with π systems, and molecular fragments able to interact with them, disrupting PPIIL propensity formation. All these modified structures had PPIIL formation propensity to enable target peptide interaction with human leukocyte antigen-DRß1* (HLA-DRß1*) molecules to mediate antigen presentation and induce an appropriate immune response. Such modified peptides were designed for human use; however, they induced high antibody titres against S, M, and E parental mutant peptides and neutralising antibodies when suitably modified and chemically synthesised for immunising 61 major histocompatibility complex class II (MHCII) DNA genotyped Aotus monkeys (matched with their corresponding HLA-DRß1* molecules), predicted to cover 77.5% to 83.1% of the world's population. Such chemically synthesised peptide mixture represents an extremely pure, stable, reliable, and cheap vaccine for COVID-19 pandemic control, providing a new approach for a logical, rational, and soundly established methodology for other vaccine development.

Validation of a duplex PCR technique using the gen E and RNase P for the diagnosis of SARS-CoV-2☆ Validación de una técnica de PCR dúplex usando el gen E y RNasa P para el diagnóstico de SARS-CoV-2

Introduction Reverse transcriptase - polymerase chain reaction (RT-PCR) is the standard technique for SARS-CoV-2 diagnosis. The World Health Organization recommends the Charité-Berlin protocol for COVID-19 diagnosis, which requires triple PCR, limiting the process capability of laboratories and delaying the results. In order to reduce these limitations, a duplex PCR is validated for the detection of the E and ribonuclease P genes. Methods We compared the limit of detection, sensitivity and specificity of the duplex PCR technique (E gene and Rnasa P) against the monoplex standard (E gene) in RNA samples from a SARS-CoV-2 isolate and 88 clinical specimens with previously known results. The repeatability and reproducibility of the threshold cycle values ​​(Ct) were determined in two independent laboratories of the Faculty of Medicine of the Universidad de Antioquia, using different reagents and real time instruments. Results There were no significant differences in the Ct results between both techniques (P = .84). Using the monoplex PCR of E gene as a reference, the interrater reliability analysis showed similarity between the two techniques, with a kappa coefficient of 0.89, the sensitivity and the specificity of duplex PCR were 90% and 87%, respectively. Conclusions Duplex PCR does not affect the sensitivity and specificity reported by the Charité, Berlin protocol, being a useful tool for SARS-CoV-2 screening in clinical samples.

Validation of a duplex PCR technique using the gen E and RNase P for the diagnosis of SARS-CoV-2.

INTRODUCTION: Reverse transcriptase - polymerase chain reaction (RT-PCR) is the standard technique for SARS-CoV-2 diagnosis. The World Health Organization recommends the Charité-Berlin protocol for COVID-19 diagnosis, which requires triple PCR, limiting the process capability of laboratories and delaying the results. In order to reduce these limitations, a duplex PCR is validated for the detection of the E and ribonuclease P genes. METHODS: We compared the limit of detection, sensitivity and specificity of the duplex PCR technique (E gene and Rnasa P) against the monoplex standard (E gene) in RNA samples from a SARS-CoV-2 isolate and 88 clinical specimens with previously known results. The repeatability and reproducibility of the threshold cycle values ​​(Ct) were determined in two independent laboratories of the Faculty of Medicine of the Universidad de Antioquia, using different reagents and real time instruments. RESULTS: There were no significant differences in the Ct results between both techniques (P = .84). Using the monoplex PCR of E gene as a reference, the interrater reliability analysis showed similarity between the two techniques, with a kappa coefficient of 0.89, the sensitivity and the specificity of duplex PCR were 90% and 87%, respectively. CONCLUSIONS: Duplex PCR does not affect the sensitivity and specificity reported by the Charité, Berlin protocol, being a useful tool for SARS-CoV-2 screening in clinical samples.

The Usefulness of Antigen Testing in Predicting Contagiousness in COVID-19.

Increasing the diagnostic capacity for COVID-19 (SARS-CoV-2 infection) is required to improve case detection, reduce COVID-19 expansion, and boost the world economy. Rapid antigen detection tests are less expensive and easier to implement, but their diagnostic performance has been questioned compared to reverse transcription-PCR (RT-PCR). Here, we evaluate the performance of the Standard Q COVID-19 antigen test for diagnosing SARS-CoV-2 infection and predicting contagiousness compared to RT-PCR and viral culture, respectively. The antigen test was 100.0% specific but only 40.9% sensitive for diagnosing infection compared to RT-PCR. Interestingly, SARS-CoV-2 contagiousness is highly unlikely with a negative antigen test since it exhibited a negative predictive value of 99.9% compared to viral culture. Furthermore, a cycle threshold (CT) value of 18.1 in RT-PCR was shown to be the one that best predicts contagiousness (area under the curve [AUC], 97.6%). Thus, screening people with antigen testing is a good approach to prevent SARS-CoV-2 contagion and allow returning to daily activities. IMPORTANCE The importance of our results is the excellent agreement between the Standard Q COVID-19 antigen test and the viral culture, indicating that it is important as a marker of contagiousness. Due to its high positive predictive value in situations of a high prevalence of infection, positive results do not require confirmation with another test. Likewise, its high negative predictive value for contagiousness makes possible to use this test as a criterion to discharge patients in isolation and screen people moving into environments that could facilitate the transmission of the virus. Screening people with antigen testing is a good approach to prevent SARS-CoV-2 contagion and allow returning to daily activities.

Immune characterization of a Colombian family cluster with SARS-CoV-2 infection. / Caracterización inmunológica de un grupo familiar colombiano con infección por SARS-CoV-2

INTRODUCTION: Immunological markers have been described during COVID-19 and persist after recovery. These immune markers are associated with clinical features among SARSCoV-2 infected individuals. Nevertheless, studies reporting a comprehensive analysis of the immune changes occurring during SARS-CoV-2 infection are still limited. OBJECTIVE: To evaluate the production of proinflammatory cytokines, the antibody response, and the phenotype and function of NK cells and T cells in a Colombian family cluster with SARS-CoV-2 infection. MATERIALS AND METHODS: Proinflammatory cytokines were evaluated by RT-PCR and ELISA. The frequency, phenotype, and function of NK cells (cocultures with K562 cells) and T-cells (stimulated with spike/RdRp peptides) were assessed by flow cytometry. Anti-SARS-CoV-2 antibodies were determined using indirect immunofluorescence and plaque reduction neutralization assay. RESULTS: During COVID-19, we observed a high proinflammatory-cytokine production and a reduced CD56bright-NK cell and cytotoxic response. Compared with healthy controls, infected individuals had a higher frequency of dysfunctional CD8+ T cells CD38+HLA-DR-. During the acute phase, CD8+ T cells stimulated with viral peptides exhibited a monofunctional response characterized by high IL-10 production. However, during recovery, we observed a bifunctional response characterized by the co-expression of CD107a and granzyme B or perforin. CONCLUSION: Although the proinflammatory response is a hallmark of SARS-CoV-2 infection, other phenotypic and functional alterations in NK cells and CD8+ T cells could be associated with the outcome of COVID-19. However, additional studies are required to understand these alterations and to guide future immunotherapy strategies.

Introducción. Se han descrito diferentes marcadores inmunológicos durante la COVID-19, los cuales persisten incluso después de la convalecencia y se asocian con los estadios clínicos de la infección. Sin embargo, aún son pocos los estudios orientados al análisis exhaustivo de las alteraciones del sistema inmunológico en el curso de la infección. Objetivo. Evaluar la producción de citocinas proinflamatorias, la reacción de anticuerpos, y el fenotipo y la función de las células NK y los linfocitos T en una familia colombiana con infección por SARS-CoV-2. Materiales y métodos. Se evaluaron las citocinas proinflamatorias mediante RT-PCR y ELISA; la frecuencia, el fenotipo y la función de las células NK (en cocultivos con células K562) y linfocitos T CD8+ (estimulados con péptidos spike/RdRp) mediante citometría de flujo, y los anticuerpos anti-SARS-CoV-2, mediante inmunofluorescencia indirecta y prueba de neutralización por reducción de placa. Resultados. Durante la COVID-19 hubo una producción elevada de citocinas proinflamatorias, con disminución de las células NK CD56bright y reacción citotóxica. Comparados con los controles sanos, los individuos infectados presentaron con gran frecuencia linfocitos T CD8+ disfuncionales CD38+HLA-DR-. Además, en los linfocitos T CD8+ estimulados con péptidos virales, predominó una reacción monofuncional con gran producción de IL-10 durante la fase aguda y una reacción bifuncional caracterizada por la coexpresión de CD107a y granzima B o perforina durante la convalecencia. Conclusión. Aunque la reacción inflamatoria caracteriza la infección por SARS-CoV-2, hay otras alteraciones fenotípicas y funcionales en células NK y linfocitos T CD8+ que podrían asociarse con la progresión de la infección. Se requieren estudios adicionales para entender estas alteraciones y guiar futuras estrategias de inmunoterapia.

The First Chemically-Synthesised, Highly Immunogenic Anti-SARS-CoV-2 Peptides in DNA Genotyped Aotus Monkeys for Human Use.

Thirty-five peptides selected from functionally-relevant SARS-CoV-2 spike (S), membrane (M), and envelope (E) proteins were suitably modified for immunising MHC class II (MHCII) DNA-genotyped Aotus monkeys and matched with HLA-DRß1* molecules for use in humans. This was aimed at producing the first minimal subunit-based, chemically-synthesised, immunogenic molecules (COLSARSPROT) covering several HLA alleles. They were predicted to cover 48.25% of the world's population for 6 weeks (short-term) and 33.65% for 15 weeks (long-lasting) as they induced very high immunofluorescent antibody (IFA) and ELISA titres against S, M and E parental native peptides, SARS-CoV-2 neutralising antibodies and host cell infection. The same immunological methods that led to identifying new peptides for inclusion in the COLSARSPROT mixture were used for antigenicity studies. Peptides were analysed with serum samples from patients suffering mild or severe SARS-CoV-2 infection, thereby increasing chemically-synthesised peptides' potential coverage for the world populations up to 62.9%. These peptides' 3D structural analysis (by 1H-NMR acquired at 600 to 900 MHz) suggested structural-functional immunological association. This first multi-protein, multi-epitope, minimal subunit-based, chemically-synthesised, highly immunogenic peptide mixture highlights such chemical synthesis methodology's potential for rapidly obtaining very pure, highly reproducible, stable, cheap, easily-modifiable peptides for inducing immune protection against COVID-19, covering a substantial percentage of the human population.

The Hydroalcoholic Extract of Uncaria tomentosa (Cat's Claw) Inhibits the Infection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) In Vitro.

The coronavirus disease 2019 (COVID-19) has become a serious problem for public health since it was identified in the province of Wuhan (China) and spread around the world producing high mortality rates and economic losses. Nowadays, the WHO recognizes traditional, complementary, and alternative medicine for treating COVID-19 symptoms. Therefore, we investigated the antiviral potential of the hydroalcoholic extract of Uncaria tomentosa stem bark from Peru against SARS-CoV-2 in vitro. The antiviral activity of U. tomentosa against SARS-CoV-2 in vitro was assessed in Vero E6 cells using cytopathic effect (CPE) and plaque reduction assay. After 48 h of treatment, U. tomentosa showed an inhibition of 92.7% of SARS-CoV-2 at 25.0 µg/mL (p < 0.0001) by plaque reduction assay on Vero E6 cells. In addition, U. tomentosa induced a reduction of 98.6% (p=0.02) and 92.7% (p=0.03) in the CPE caused by SARS-CoV-2 on Vero E6 cells at 25 µg/mL and 12.5 µg/mL, respectively. The EC50 calculated for the U. tomentosa extract by plaque reduction assay was 6.6 µg/mL (4.89-8.85 µg/mL) for a selectivity index of 4.1. The EC50 calculated for the U. tomentosa extract by TCID50 assay was 2.57 µg/mL (1.05-3.75 µg/mL) for a selectivity index of 10.54. These results showed that U. tomentosa, known as cat's claw, has an antiviral effect against SARS-CoV-2, which was observed as a reduction in the viral titer and CPE after 48 h of treatment on Vero E6 cells. Therefore, we hypothesized that U. tomentosa stem bark could be promising in the development of new therapeutic strategies against SARS-CoV-2.

Validation of a duplex PCR technique using the gen E and RNase P for the diagnosis of SARS-CoV-2. / Validación de una técnica de PCR dúplex usando el gen E y RNasa P para el diagnóstico de SARS-CoV-2.

INTRODUCTION: Reverse transcriptase - polymerase chain reaction (RT-PCR) is the standard technique for SARS-CoV-2 diagnosis. The World Health Organization recommends the Charité-Berlin protocol for COVID-19 diagnosis, which requires triple PCR, limiting the process capability of laboratories and delaying the results. In order to reduce these limitations, a duplex PCR is validated for the detection of the E and RNase P genes. METHODS: We compared the limit of detection, sensitivity and specificity of the duplex PCR technique (E gene and RNase P) against the monoplex standard (E gene) in RNA samples from a SARS-CoV-2 isolate and 88 clinical specimens with previously known results. The repeatability and reproducibility of the threshold cycle values (Ct) were determined in two independent laboratories of the Faculty of Medicine of the Universidad de Antioquia, using different reagents and real time instruments. RESULTS: There were no significant differences in the Ct results between both techniques (p = 0.84). Using the monoplex PCR of E gene as a reference, the interrater reliability analysis showed similarity between the two techniques, with a kappa coefficient of 0.89, the sensitivity and the specificity of duplex PCR were 90% and 87%, respectively. CONCLUSIONS: Duplex PCR does not affect the sensitivity and specificity reported by the Charité, Berlin protocol, being a useful tool for SARS-CoV-2 screening in clinical samples.

Isolation and characterization of an early SARS-CoV-2 isolate from the 2020 epidemic in Medellín, Colombia

Resumen Introducción. El nuevo coronavirus causante de un brote de enfermedad respiratoria aguda en China en diciembre de 2019 se identificó como SARS-CoV-2. La enfermedad, denominada COVID-19, fue declarada pandemia por la Organización Mundial de la Salud (OMS). El primer caso de COVID-19 en Colombia se reportó el 6 de marzo de 2020;en este estudio se caracterizó un aislamiento temprano del virus SARS-CoV-2 de una muestra recolectada en abril de 2020. Objetivos. Describir y caracterizar una cepa temprana a partir de un aislamiento de SARS-CoV-2 durante la pandemia en Colombia. Materiales y métodos. Se obtuvo una muestra de un paciente con COVID-19 confirmada por qRT-PCR;la muestra fue inoculada en diferentes líneas celulares hasta la aparición del efecto citopático. Para confirmar la presencia de SARS-CoV-2 en el cultivo, se utilizó la qRT-PCR a partir de los sobrenadantes, la inmunofluorescencia indirecta (IFI) en células Vero-E6, así como microscopía electrónica y secuenciación de nueva generación (next-generation sequencing). Resultados. Se confirmó el aislamiento de SARS-CoV-2 en células Vero-E6 por la aparición del efecto citopático tres días después de la infección, así como mediante la qRT-PCR y la IFI positiva con suero de paciente convaleciente positivo para SARS-CoV-2. Además, en las imágenes de microscopía electrónica de trasmisión y de barrido de células infectadas se observaron estructuras compatibles con viriones de SARS-CoV-2. Por último, se obtuvo la secuencia completa del genoma, lo que permitió clasificar el aislamiento como linaje B.1.5. Conclusiones. La evidencia presentada en este artículo permite confirmar el primer aislamiento de SARS-CoV-2 en Colombia. Además, muestra que esta cepa se comporta en cultivo celular de manera similar a lo reportado en la literatura para otros aislamientos y que su composición genética está acorde con la variante predominante en el mundo. Finalmente, se resalta la importancia que tiene el aislamiento viral para la detección de anticuerpos, para la caracterización genotípica y fenotípica de la cepa y para probar compuestos con potencial antiviral. Introduction: SARS-CoV-2 has been identified as the new coronavirus causing an outbreak of acute respiratory disease in China in December, 2019. This disease, currently named COVID-19, has been declared as a pandemic by the World Health Organization (WHO). The first case of COVID-19 in Colombia was reported on March 6, 2020. Here we characterize an early SARS-CoV-2 isolate from the pandemic recovered in April, 2020. Objective: To describe the isolation and characterization of an early SARS-CoV-2 isolate from the epidemic in Colombia. Materials and methods: A nasopharyngeal specimen from a COVID-19 positive patient was inoculated on different cell lines. To confirm the presence of SARS-CoV-2 on cultures we used qRT-PCR, indirect immunofluorescence assay, transmission and scanning electron microscopy, and next-generation sequencing. Results: We determined the isolation of SARS-CoV-2 in Vero-E6 cells by the appearance of the cytopathic effect three days post-infection and confirmed it by the positive results in the qRT-PCR and the immunofluorescence with convalescent serum. Transmission and scanning electron microscopy images obtained from infected cells showed the presence of structures compatible with SARS-CoV-2. Finally, a complete genome sequence obtained by next-generation sequencing allowed classifying the isolate as B.1.5 lineage. Conclusion: The evidence presented in this article confirms the first isolation of SARS-CoV-2 in Colombia. In addition, it shows that this strain behaves in cell culture in a similar way to that reported in the literature for other isolates and that its genetic composition is consistent with the predominant variant in the world. Finally, points out the importance of viral isolation for the detection of neutralizing antibodies, for the genotypic and phenotypic characterization of the strain and for testing compounds with antiviral potential.

Isolation and characterization of an early SARS-CoV-2 isolate from the 2020 epidemic in Medellín, Colombia / [Aislamiento y caracterización de una cepa temprana de SARS-CoV-2 durante la epidemia de 2020 en Medellín, Colombia].

Introduction: SARS-CoV-2 has been identified as the new coronavirus causing an outbreak of acute respiratory disease in China in December, 2019. This disease, currently named COVID-19, has been declared as a pandemic by the World Health Organization (WHO). The first case of COVID-19 in Colombia was reported on March 6, 2020. Here we characterize an early SARS-CoV-2 isolate from the pandemic recovered in April, 2020. Objective: To describe the isolation and characterization of an early SARS-CoV-2 isolate from the epidemic in Colombia. Materials and methods: A nasopharyngeal specimen from a COVID-19 positive patient was inoculated on different cell lines. To confirm the presence of SARS-CoV-2 on cultures we used qRT-PCR, indirect immunofluorescence assay, transmission and scanning electron microscopy, and next-generation sequencing. Results: We determined the isolation of SARS-CoV-2 in Vero-E6 cells by the appearance of the cytopathic effect three days post-infection and confirmed it by the positive results in the qRT-PCR and the immunofluorescence with convalescent serum. Transmission and scanning electron microscopy images obtained from infected cells showed the presence of structures compatible with SARS-CoV-2. Finally, a complete genome sequence obtained by next-generation sequencing allowed classifying the isolate as B.1.5 lineage. Conclusion: The evidence presented in this article confirms the first isolation of SARSCoV-2 in Colombia. In addition, it shows that this strain behaves in cell culture in a similar way to that reported in the literature for other isolates and that its genetic composition is consistent with the predominant variant in the world. Finally, points out the importance of viral isolation for the detection of neutralizing antibodies, for the genotypic and phenotypic characterization of the strain and for testing compounds with antiviral potential.

Introducción. El nuevo coronavirus causante de un brote de enfermedad respiratoria aguda en China en diciembre de 2019 se identificó como SARS-CoV-2. La enfermedad, denominada COVID-19, fue declarada pandemia por la Organización Mundial de la Salud (OMS). El primer caso de COVID-19 en Colombia se reportó el 6 de marzo de 2020; en este estudio se caracterizó un aislamiento temprano del virus SARS-CoV-2 de una muestra ecolectada en abril de 2020. Objetivos. Describir y caracterizar una cepa temprana a partir de un aislamiento de SARSCoV-2 durante la pandemia en Colombia. Materiales y métodos. Se obtuvo una muestra de un paciente con COVID-19 confirmada por qRT-PCR; la muestra fue inoculada en diferentes líneas celulares hasta la aparición del efecto citopático. Para confirmar la presencia de SARS-CoV-2 en el cultivo, se utilizó la qRT-PCR a partir de los sobrenadantes, la inmunofluorescencia indirecta (IFI) en células Vero-E6, así como microscopía electrónica y secuenciación de nueva generación (nextgeneration sequencing). Resultados. Se confirmó el aislamiento de SARS-CoV-2 en células Vero-E6 por la aparición del efecto citopático tres días después de la infección, así como mediante la qRT-PCR y la IFI positiva con suero de paciente convaleciente positivo para SARS-CoV-2. Además, en las imágenes de microscopía electrónica de trasmisión y de barrido de células infectadas se observaron estructuras compatibles con viriones de SARS-CoV-2. Por último, se obtuvo la secuencia completa del genoma, lo que permitió clasificar el aislamiento como linaje B.1.5. Conclusiones. La evidencia presentada en este artículo permite confirmar el primer aislamiento de SARS-CoV-2 en Colombia. Además, muestra que esta cepa se comporta en cultivo celular de manera similar a lo reportado en la literatura para otros aislamientos y que su composición genética está acorde con la variante predominante en el mundo. Finalmente, se resalta la importancia que tiene el aislamiento viral para la detección de anticuerpos, para la caracterización genotípica y fenotípica de la cepa y para probar compuestos con potencial antiviral.