Browsing by Author "Melo González, Felipe"

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    Humoral and cellular response induced by a second booster of an inactivated SARS-CoV-2 vaccine in adults
    (2022) Melo González, Felipe; Méndez, Constanza; Peñaloza, H.F.; Schultz, B.M.; Piña Iturbe, A.; Ríos, M.; Moreno Tapia, D.; Pereira Sánchez, P.; Leighton, D.; Orellana, C.; Covarrubias, C.; Gálvez, N.M.S.; Soto, J.A.; Duarte, L.F.; Rivera Pérez, D.; Vázquez, Y.; Cabrera, A.; Bustos, S.; Iturriaga, C.; Urzua, M.; Navarrete, M.S.; Rojas, Á.; Fasce, R.; Fernández, J.; Mora, J.; Ramírez, E.; Gaete Argel, A.; Acevedo, M.; Valiente Echeverría, F.; Soto Rifo, R.; Weiskopf, D.; Grifoni, A.; Sette, A.; Zeng, G.; Meng, W.; González Aramundiz, J.V.; González, P.A.; Abarca, K.; Bueno, S.M.; Kalergis, A.M.
    The SARS-CoV-2 Omicron variant has challenged the control of the COVID-19 pandemic even in highly vaccinated countries. While a second booster of mRNA vaccines improved the immunity against SARS-CoV-2, the humoral and cellular responses induced by a second booster of an inactivated SARS-CoV-2 vaccine have not been studied. In the context of a phase 3 clinical study, we report that a second booster of CoronaVac® increased the neutralizing response against the ancestral virus yet showed poor neutralization against the Omicron variant. Additionally, isolated PBMCs displayed equivalent activation of specific CD4+ T cells and IFN-γ production when stimulated with a mega-pool of peptides derived from the spike protein of the ancestral virus or the Omicron variant. In conclusion, a second booster dose of CoronaVac® does not improve the neutralizing response against the Omicron variant compared with the first booster dose, yet it helps maintaining a robust spike-specific CD4+ T cell response.
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    Interim report: Safety and immunogenicity of an inactivated vaccine against SARS-CoV-2 in healthy chilean adults in a phase 3 clinical trial
    (2021) Bueno Ramírez, Susan; Abarca Villaseca, Katia; González Adonis, Pablo Andrés; Gálvez Arriagada, Nicolás Marcelo Salvador; Soto Ramírez, Jorge Andrés; Duarte Peñaloza, Luisa Fernanda; Schultz Lombardic, Bárbara M.; Pacheco, Gaspar A.; González Carreño, Liliana Andrea; Vázquez, Yaneisi; Ríos Raggio, Mariana; Melo González, Felipe; Rivera Pérez, Daniela; Iturriaga, Carolina; Urzúa Acevedo, Marcela del Pilar; Domínguez De Landa, María Angélica; Andrade Parra, Catalina Andrea; Berríos Rojas, Roslye; Canedo Marroquín, Giselda; Covián, Camila
    The ongoing COVID-19 pandemic has had a significant impact worldwide, with an incommensurable social and economic burden. The rapid development of safe and protective vaccines against this disease is a global priority. CoronaVac is a vaccine prototype based on inactivated SARS-CoV-2, which has shown promising safety and immunogenicity profiles in pre-clinical studies and phase 1/2 trials in China. To this day, four phase 3 clinical trials are ongoing with CoronaVac in Brazil, Indonesia, Turkey, and Chile. This article reports the safety and immunogenicity results obtained in a subgroup of participants aged 18 years and older enrolled in the phase 3 Clinical Trial held in Chile.
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    Reduced Immune Response to Inactivated Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine in a Cohort of Immunocompromised Patients in Chile
    (Oxford University Press for the Infectious Diseases Society of America, 2022) Balcells Marty, María Elvira; Le Corre Pérez, Monique Nicole; Durán Santa Cruz, Josefina Gracia; Ceballos Valdivielso, María Elena Andrea; Vizcaya Altamirano, María Cecilia; Mondaca Contreras, Sebastián Patricio; Dib Marambio, Martin Javier; Rabagliati Borie, Ricardo Miguel; Sarmiento Maldonado, Mauricio; Burgos Cañete, Paula Isabel; Espinoza Sepúlveda, Manuel Antonio; Ferres Garrido, Marcela Viviana; Martínez Valdebenito, Constanza Pamela; Ruiz-Tagle Seguel, Cinthya Grace; Ortiz Koh, Catalina Alejandra; Ross Pérez, Patricio Daniel; Budnik Bitran, Sigall; Solari Gajardo, Sandra; Vizcaya Vergara, María De Los Ángeles; Lembach, Hanns; Berríos Rojas, Roslye; Melo González, Felipe; Rios Raggio, Mariana; Kalergis Parra, Alexis Mikes; Bueno Ramírez, Susan Marcela; Nervi Nattero, Bruno
    Background Inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines have been widely implemented in low- and middle-income countries. However, immunogenicity in immunocompromised patients has not been established. Herein, we aimed to evaluate immune response to CoronaVac vaccine in these patients. Methods This prospective cohort study included 193 participants with 5 different immunocompromising conditions and 67 controls, receiving 2 doses of CoronaVac 8-12 weeks before enrollment. The study was conducted between May and August 2021, at Red de Salud UC-CHRISTUS, Santiago, Chile. Neutralizing antibody (NAb) positivity, total anti-SARS-CoV-2 immunoglobulin G antibody (TAb) concentrations, and T-cell responses were determined. Results NAb positivity and median neutralizing activity were 83.1% and 51.2% for the control group versus 20.6% and 5.7% (both P < .001) in the solid organ transplant group, 41.5% and 19.2% (both P < .0001) in the autoimmune rheumatic diseases group, 43.3% (P < .001) and 21.4% (PP = .001) in the cancer with solid tumors group, 45.5% and 28.7% (both P < .001) in the human immunodeficiency virus (HIV) infection group, 64.3% and 56.6% (both differences not significant) in the hematopoietic stem cell transplant group, respectively. TAb seropositivity was also lower for the solid organ transplant (20.6%; P < .0001), rheumatic diseases (61%; P < .001), and HIV groups (70.9%; P = .003), compared with the control group (92.3%). On the other hand, the number of interferon gamma spot-forming T cells specific for SARS-CoV-2 tended to be lower in all immunocompromising conditions but did not differ significantly between groups. Conclusions Diverse immunocompromising conditions markedly reduce the humoral response to CoronaVac vaccine. These findings suggest that a boosting vaccination strategy should be considered in these vulnerable patients.