Browsing by Author "Potin, Marcela"
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Item Declaración del Comité Consultivo de Inmunizaciones de Sociedad Chilena de Infectología en relación a los cuestionamientos de las vacunas y su obligatoriedad(2017) Wilhelm, Jan; Calvo, Ximena; Escobar, Carola; Moreno, Gabriela; Véliz, Liliana; Villena, Rodolfo; Potin, MarcelaA pesar del enorme impacto de las vacunas en la salud de la población, éstas han sido y son objeto de cuestionamientos por grupos que las consideran innecesarias o inseguras y argumentan que las personas tienen el derecho a decidir sobre si éstas deben ser administradas o no. Sin embargo, el uso de vacunas tiene connotaciones distintas a otras decisiones en salud, ya que no vacunar impacta no sólo al individuo, sino también a la comunidad que lo rodea. El inmunizar a un alto porcentaje de la población permite limitar la circulación de los agentes infecciosos, logrando la llamada inmunidad comunitaria que protege a los no vacunados por razones médicas o porque son muy pequeños. Por esta razón muchos países han definido las vacunas como obligatorias. Como Comité Consultivo de Inmunizaciones nos parece que esta estrategia es correcta; sin embargo, debe ser acompañada por una política de educación de la población y personal de salud sobre los beneficios y riesgos reales de las vacunas. Así mismo es necesario introducir mejoras en el sistema de notificación de reacciones adversas a vacunas haciéndolo más accesible. Adicionalmente, se debe dar respuesta oportuna a los afectados por supuestas o reales reacciones a vacunas, y en los casos de eventos adversos graves efectivamente asociados a vacunas. entregar cobertura económica y acompañamiento. Finalmente, es esencial la coordinación entre los diferentes actores y comunicadores para transmitir mensajes que generen confianza y respondan a las inquietudes de la población de hoy en día.Publication Different Safety Pattern of an Inactivated SARS-CoV-2 Vaccine (CoronaVac®) According to Age Group in a Pediatric Population from 3 to 17 Years Old, in an Open-Label Study in Chile(2023) Le Corre, Nicole; Abarca, Katia; Astudillo, Patricio; Potin, Marcela; López, Sofía; Goldsack, Macarena; Valenzuela, Vania; Schilling Redlich, Andrea; Gaete, Victoria; Rubio, Lilian; Calvo, Mario; Twele, Loreto; González, Marcela; Fuentes, Daniela; Gutiérrez, Valentina; Reyes, Felipe; Tapia, Lorena I.; Villena, Rodolfo; Retamal-Díaz, Angello; Cárdenas, Antonio; Alarcón-Bustamante, Eduardo; Meng, Xing; Xin, Qianqian; González-Aramundiz, José V.; Alvarez-Figueroa, María Javiera; González, Pablo A.; Bueno, Susan M.; Soto, Jorge A.; on behalf of the PedCoronaVac03CL Study Group; Perret, Cecilia; Kalergis, Alexis M.During the COVID-19 pandemic, the importance of vaccinating children against SARS-CoV-2 was rapidly established. This study describes the safety of CoronaVac® in children and adolescents between 3- and 17-years-old in a multicenter study in Chile with two vaccine doses in a 4-week interval. For all participants, immediate adverse events (AEs), serious AEs (SAEs), and AEs of special interest (AESIs) were registered throughout the study. In the safety subgroup, AEs were recorded 28 days after each dose. COVID-19 surveillance was performed throughout the study. A total of 1139 individuals received the first and 1102 the second dose of CoronaVac®; 835 were in the safety subgroup. The first dose showed the highest number of AEs: up to 22.2% of participants reported any local and 17.1% systemic AE. AEs were more frequent in adolescents after the first dose, were transient, and mainly mild. Pain at the inoculation site was the most frequent AE for all ages. Fever was the most frequent systemic AE for 3–5 years old and headache in 6–17 years old. No SAEs or AESIs related to vaccination occurred. Most of the COVID-19 cases were mild and managed as outpatients. CoronaVac® was safe and well tolerated in children and adolescents, with different safety patterns according to age.Publication Inactivated Vaccine-Induced SARS-CoV-2 Variant-Specific Immunity in Children(2022) Soto, Jorge; Melo, Felipe; Gutierrez, Cristián; Schultz, Bárbara; Berríos, Roslye; Rivera, Daniela; Piña, Alejandro; Hoppe, Guillermo; Duarte, Luisa; Vázquez, Yaneisi; Moreno, Daniela; Ríos, Mariana; Palacios, Pablo; Garcia, Richard; Santibañez, Álvaro; Pacheco, Gaspar; Mendez, Constanza; Andrade, Catalina; Silva, Pedro; Diethelm, Benjamín; Astudillo, Patricio; Calvo, Mario; Cárdenas, Antonio; González, Marcela; Goldsack, Macarena; Gutiérrez, Valentina; Potin, Marcela; Schilling, Andrea; Tapia, Lorena; Twele, Loreto; Villena, Rodolfo; Grifoni, Alba; Sette, Alessandro; Weiskopf, Daniela; Fasce, Rodrigo; Fernández, Jorge; Mora, Judith; Ramírez, Eugenio; Gaete, Aracelly; Acevedo, Mónica; Valiente, Fernando; Soto, Ricardo; Retamal, Angello; Muñoz, Nathalia; PedCoronaVac03CL Study Group; Meng, Xing; Xin, Qianqian; Alarcón, Eduardo; González, José; Le Corre, Nicole; Álvarez, María; González, Pablo; Abarca, Katia; Perret, Cecilia; Carreño, Leandro; Bueno, Susan; Kalergisa, AlexisMultiple vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been evaluated in clinical trials. However, trials addressing the immune response in the pediatric population are scarce. The inactivated vaccine CoronaVac has been shown to be safe and immunogenic in a phase 1/2 clinical trial in a pediatric cohort in China. Here, we report interim safety and immunogenicity results of a phase 3 clinical trial for CoronaVac in healthy children and adolescents in Chile. Participants 3 to 17 years old received two doses of CoronaVac in a 4-week interval until 31 December 2021. Local and systemic adverse reactions were registered for volunteers who received one or two doses of CoronaVac. Whole-blood samples were collected from a subgroup of 148 participants for humoral and cellular immunity analyses. The main adverse reaction reported after the first and second doses was pain at the injection site. Four weeks after the second dose, an increase in neutralizing antibody titer was observed in subjects relative to their baseline visit. Similar results were found for activation of specific CD4+ T cells. Neutralizing antibodies were identified against the Delta and Omicron variants. However, these titers were lower than those for the D614G strain. Importantly, comparable CD4+ T cell responses were detected against these variants of concern. Therefore, CoronaVac is safe and immunogenic in subjects 3 to 17 years old, inducing neutralizing antibody secretion and activating CD4+ T cells against SARS-CoV-2 and its variants. (This study has been registered at ClinicalTrials.gov under no. NCT04992260.) IMPORTANCE This work evaluated the immune response induced by two doses of CoronaVac separated by 4 weeks in healthy children and adolescents in Chile. To date, few studies have described the effects of CoronaVac in the pediatric population. Therefore, it is essential to generate knowledge regarding the protection of vaccines in this population. Along these lines, we reported the anti-S humoral response and cellular immune response to several SARS-CoV-2 proteins that have been published and recently studied. Here, we show that a vaccination schedule consisting of two doses separated by 4 weeks induces the secretion of neutralizing antibodies against SARS-CoV-2. Furthermore, CoronaVac induces the activation of CD4+ T cells upon stimulation with peptides from the proteome of SARS-CoV-2. These results indicate that, even though the neutralizing antibody response induced by vaccination decreases against the Delta and Omicron variants, the cellular response against these variants is comparable to the response against the ancestral strain D614G, even being significantly higher against Omicron.Item Safety and Immunogenicity of an Inactivated Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine in a Subgroup of Healthy Adults in Chile(2021) Bueno, Susan M.; Abarca, Katia; González, Pablo A.; Gálvez, Nicolás M. S.; Soto, Jorge A.; Duarte, Luisa F.; Schultz, Bárbara M.; Pacheco, Gaspar A.; González, Liliana A.; Vázquez, Yaneisi; Ríos, Mariana; Melo-González, Felipe; Rivera-Pérez, Daniela; Iturriaga, Carolina; Urzúa, Marcela; Domínguez, Angélica; Andrade, Catalina A.; Berríos-Rojas, Roslye V.; Canedo-Marroquín, Gisela; Covián, Camila; Moreno-Tapia, Daniela; Saavedra, Farides; Vallejos, Omar P.; Donato, Paulina; Espinoza, Pilar; Fuentes, Daniela; González, Marcela; Guzmán, Paula; Muñoz Venturelli, Paula; Pérez, Carlos M.; Potin, Marcela; Rojas, Álvaro; Fasce, Rodrigo A.; Fernández, Jorge; Mora, Judith; Ramírez, Eugenio; Gaete-Argel, Aracely; Oyarzún-Arrau, Aarón; Soto-Rifo, Ricardo; Weiskopf, Daniela; Sette, Alessandro; Zeng, Gang; Meng, Weining; González-Aramundiz, José V.; Kalergis, Alexis M.; CoronaVac03CL Study GroupBackground. The development of effective vaccines against coronavirus disease 2019 is a global priority. CoronaVac is an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine with promising safety and immunogenicity profiles. This article reports safety and immunogenicity results obtained for healthy Chilean adults aged ≥18 years in a phase 3 clinical trial. Methods. Volunteers randomly received 2 doses of CoronaVac or placebo, separated by 2 weeks. A total of 434 volunteers were enrolled, 397 aged 18–59 years and 37 aged ≥60 years. Solicited and unsolicited adverse reactions were registered from all volun- teers. Blood samples were obtained from a subset of volunteers and analyzed for humoral and cellular measures of immunogenicity. Results. The primary adverse reaction in the 434 volunteers was pain at the injection site, with a higher incidence in the vaccine than in the placebo arm. Adverse reactions observed were mostly mild and local. No severe adverse events were reported. The humoral evaluation was performed on 81 volunteers. Seroconversion rates for specific anti-S1-receptor binding domain (RBD) immunoglobulin G (IgG) were 82.22% and 84.44% in the 18–59 year age group and 62.69% and 70.37% in the ≥60 year age group, 2 and 4 weeks after the second dose, respectively. A significant increase in circulating neutralizing antibodies was detected 2 and 4 weeks after the second dose. The cellular evaluation was performed on 47 volunteers. We detected a significant induction of T-cell responses characterized by the secretion of interferon-γ (IFN-γ) upon stimulation with Mega Pools of peptides from SARS-CoV-2. Conclusions. Immunization with CoronaVac in a 0–14 schedule in Chilean adults aged ≥18 years is safe, induces anti-S1-RBD IgG with neutralizing capacity, activates T cells, and promotes the secretion of IFN-γ upon stimulation with SARS-CoV-2 antigens.Publication Safety and Non-Inferiority Evaluation of Two Immunization Schedules with an Inactivated SARS-CoV-2 Vaccine in Adults: A Randomized Clinical Trial(2022) Abarca, Katia; Iturriaga, Carolina; Urzúa, Marcela; Le Corre, Nicole; Pineda, Augusto; Fernández, Carolina; Domínguez, Angélica; González, Pablo; Bueno, Susan; Donato, Paulina; Espinoza, Pilar; Fuentes, Daniela; González, Marcela; Guzmán, Paula; Muñoz Venturelli, Paula; Pérez, Carlos; Potin, Marcela; Rojas, Álvaro; González, José; Gálvez, Nicolás; Aguirre, Francisca; Aljaro, Sofía; Bátiz, Luis; Campisto, Yessica; Cepeda, Mariela; Cortés, Aarón; López, Sofía; Pérez, María; Schilling, Andrea; Kalergis, Alexis; On behalf of the CoronaVac CL Study GroupSeveral vaccines have been developed to control the COVID-19 pandemic. CoronaVac®, an inactivated SARS-CoV-2 vaccine, has demonstrated safety and immunogenicity, preventing severe COVID-19 cases. We investigate the safety and non-inferiority of two immunization schedules of CoronaVac® in a non-inferiority trial in healthy adults. A total of 2302 healthy adults were enrolled at 8 centers in Chile and randomly assigned to two vaccination schedules, receiving two doses with either 14 or 28 days between each. The primary safety and efficacy endpoints were solicited adverse events (AEs) within 7 days of each dose, and comparing the number of cases of SARS-CoV-2 infection 14 days after the second dose between the schedules, respectively. The most frequent local AE was pain at the injection site, which was less frequent in participants aged ≥60 years. Other local AEs were reported in less than 5% of participants. The most frequent systemic AEs were headache, fatigue, and myalgia. Most AEs were mild and transient. There were no significant differences for local and systemic AEs between schedules. A total of 58 COVID-19 cases were confirmed, and all but 2 of them were mild. No differences were observed in the proportion of COVID-19 cases between schedules. CoronaVac® is safe, especially in ≥60-year-old participants. Both schedules protected against COVID-19 hospitalization.