Examinando por Autor "Silva, Viviana"

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    Ítem
    Humoral and cellular response induced by a second booster of an inactivated SARS-CoV-2 vaccine in adults
    (Elsevier B.V., 2023-05) Méndez, Constanza; Peñaloza, Hernán F.; Schultz, Bárbara M.; Piña-Iturbe, Alejandro; Ríos, Mariana; Moreno-Tapia, Daniela; Pereira-Sánchez, Patricia; Leighton, Diane; Orellana, Claudia; Covarrubias, Consuelo; Gálvez, Nicolás M.S.; Soto, Jorge A.; Duarte, Luisa F.; Rivera-Pérez, Daniela; Vázquez, Yaneisi; Cabrera, Alex; Bustos, Sergio; Iturriaga, Carolina; Urzua, Marcela; Navarrete, María S.; Rojas, Álvaro; Fasce, Rodrigo A.; Fernández, Jorge; Mora, Judith; Ramírez, Eugenio; Gaete-Argel, Aracelly; Acevedo, Mónica; Valiente-Echeverría, Fernando; Soto-Rifo, Ricardo; Weiskopf, Daniela; Grifoni, Alba; Sette, Alessandro; Zeng, Gang; Meng, Weining; Del Río, Constanza; Del Pino, Dinely; Aguirre, Natalia; Salinas, Grecia; Vega, Franco; Salgado, Acsa; Quinteros, Thomas; Ortiz, Marlene; Puente, Marcela; Muñoz, Alma; Astudillo, Patricio; Le Corre, Nicole; Potin, Marcela; Catalán, Juan; Peralta, Melan; Zamanillo, Consuelo; Keller, Nicole; Fernández, Rocío; Aljaro, Sofía; López, Sofía; González, José Tomás; Weil, Tania; Opazo, Luz; Muñoz, Paula; Estay, Inés; Cantillana, Miguel; Carrera, Liliana; Masalleras, Matías; Guzmán, Paula; Aguirre, Francisca; Cortés, Aarón; Bátiz, Luis Federico; Pérez, Javiera; Apablaza, Karen; Yates, Lorena; Valdés, María de los Ángeles; Hurtado, Bernardita; Venteneul, Veronique; Astorga, Constanza; Muñoz-Venturelli, Paula; Vial, Pablo A.; Schilling, Andrea; Pavez, Daniela; Pérez, Inia; Riviotta, Amy; González, Francisca; Urrutia, Francisca; Del Río, Alejandra; Asenjo, Claudia; Vargas, Bárbara; Castro, Francisca; Acuña, Alejandra; Guzmán, Javiera; Astudillo, Camila; Pérez, Carlos M.; Espinoza, Pilar; Martínez, Andrea; Arancibia, Marcela; Romero, Harold; Bustamante, Cecilia; Pérez, María Loreto; Uribe, Natalia; Silva, Viviana; Morice, Bernardita; Pérez, Marco; González, Marcela; Jensen, Werner; Pasten, Claudia; Aguilera, M. Fernanda; Martínez, Nataly; Molina, Camila; Arrieta, Sebastián; López, Begoña; Ortiz, Claudia; Escobar, Macarena; Bustamante, Camila; Espinoza, Marcia; Pardo, Angela; Carrasco, Alison; Montes, Miguel; Saldías, Macarena; Gutiérrez, Natalia; Sánchez, Juliette; Fuentes, Daniela; Calvo, Yolanda; Cepeda, Mariela; Lemus, Rosario; Suárez, Muriel; Armijo, Mercedes; Monsalves, Shirley; Marucich, Constance; Cornejo, Cecilia; Acosta, Ángela; Prado, Xaviera; Yáñez, Francisca; Barroeta, Marisol; López, Claudia; Donato, Paulina; Lasso, Martin; Iturrieta, María; Giraldo, Juan; Gutiérrez, Francisco; Acuña, María; Cascone, Ada; Rojas, Raymundo; Sepúlveda, Camila; Contreras, Mario; Campisto, Yessica; González, Pablo A.; Quizhpi, Zoila; López, Mariella; Pizzeghello, Vania; Silva, Stephannie; González-Aramundiz, José V.; Abarca, Katia; Melo-González, Felipe; Bueno, Susan M.; Kalergis, Alexis M.
    Background: The Omicron variant has challenged the control of the COVID-19 pandemic due to its immuno-evasive properties. The administration of a booster dose of a SARS-CoV-2 vaccine showed positive effects in the immunogenicity against SARS-CoV-2, effect that is even enhanced after the administration of a second booster. Methods: During a phase-3 clinical trial, we evaluated the effect of a second booster of CoronaVac®, an inactivated vaccine administered 6 months after the first booster, in the neutralization of SARS-CoV-2 (n = 87). In parallel, cellular immunity (n = 45) was analyzed in stimulated peripheral mononuclear cells by flow cytometry and ELISPOT. Findings: Although a 2.5-fold increase in neutralization of the ancestral SARS-CoV-2 was observed after the second booster when compared with prior its administration (Geometric mean units p < 0.0001; Geometric mean titer p = 0.0002), a poor neutralization against the Omicron variant was detected. Additionally, the activation of specific CD4+ T lymphocytes remained stable after the second booster and, importantly, equivalent activation of CD4+ T lymphocytes against the Omicron variant and the ancestral SARS-CoV-2 were found. Interpretation: Although the neutralizing response against the Omicron variant after the second booster of CoronaVac® was slightly increased, these levels are far from those observed against the ancestral SARS-CoV-2 and could most likely fail to neutralize the virus. In contrast, a robust CD4+T cell response may confer protection against the Omicron variant. Funding: The Ministry of Health, Government of Chile, the Confederation of Production and Commerce, Chile and SINOVAC Biotech. NIH NIAID. The Millennium Institute on Immunology and Immunotherapy. © 2023 The Author(s)
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    Ítem
    Prevalencia y perfil de susceptibilidad antimicrobiana en bacterias aisladas de úlceras crònicas infectadas en adultos
    (Sociedad Chilena de Infectologia, 2018-04) Silva, Víctor; Marcoleta, Alicia; Silva, Viviana; Flores, Dángelo; Aparicio, Teresa; Aburto, Isabel; Latrach, Cecilia; Febré, Naldy
    Background: Chronic wounds are considered a public health problem that may be complicated by bacterial infections, mainly caused by resistant strains. Aim: To study the bacteria prevalence and antimicrobial susceptibility in samples from adult patients with chronic wounds. Methods: Patients treated at National Institute of Wounds Foundation between May and July 2014, with chronic ulcers in lower extremities with clinical inflammatory signs were recluted. Samples were cultured in aerobic and anaerobic atmosphere and species identification was performed by API (Biomerieux) galleries. The in vitro susceptibility was evaluated according to the Kirby Bauer method. Results: From 73 patients, 46 had infected wounds most of them were venous ulcers (33) with prevalence in polymicrobial infections and 10 with foot-diabetes ulcers with prevalence in monomicrobial infections (p . 0.05). Sixty-eight strains were isolated and Enterobacteriaceae were predominant in monomicrobial infection (p . 0.05) and the other groups were slightly higher in polymicrobial infection. The main species were Staphylococcus aureus (24%) followed by P. aeruginosa (18%). Fifty strains (77%) were resistant or multi-resistance. We emphasize resistance of S. aureus to ciprofloxacin (50%) and cefoxitin (37.5%), thus identifying resistance to methicillin in the community (CA-SAMR), all of which are sensitive to cotrimoxazole. Enterobacteria showed sensitivity to amikacin (95.5%), P. aeruginosa showed resistance to ciprofloxacin (33.3%) with high sensitivity to gentamicin (91.7%) and amikacin (83.3%), while Acinetobacter spp showed resistance to ciprofloxacin and ceftazidime in 60%, with 100% sensitivity to imipenem. 50% Streptococcus β hemolytic showed resistance to clindamycin and penicillin. Conclusion: These data provide epidemiological information on chronic wound infections, representing support for diagnosis, treatment and management of this pathology. © 2018, Sociedad Chilena de Infectologia. All rights reserved.