Browsing by Author "Vázquez Hernández, Yaneisi"

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    Differential Sars-cov-2 antigen specificity of the humoral response inactivated virus-vaccinated, convalescent, and breakthrough subjects
    (2022) Duarte Peñaloza, Luisa Fernanda; Vázquez Hernández, Yaneisi; Diethelm Varela, Benjamin Manuel; Pávez Carrasco, Valentina Ignacia; Berrios Rojas, Roslye; White, Jessica A.; Kalergis Parra, Alexis Mikes; Bueno Ramírez, Susan Marcela; Gonzalez Munoz, Pablo Alberto
    Analytical methods for the differential determination between natural infection with SARS- CoV-2 vs. immunity elicited by vaccination or infection after immunization (breakthrough cases) represent attractive new research venues in the context of the ongoing COVID-19 pandemic caused by Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2). Herein, we set out to compare humoral responses against several SARS-CoV-2 structural and non-structural proteins in infected unvaccinated (convalescent), vaccinated, as well as vaccinated and infected (breakthrough) individuals. Our results indicate that immunization with an inactivated SARS-CoV-2 vaccine (CoronaVac) induces significantly higher levels of IgG antibodies against the membrane (M) protein of SARS-CoV-2 as compared to convalescent subjects both, after the primary vaccination schedule and after a booster dose. Moreover, we found that CoronaVac-immunized individuals, after receiving a third vaccine shot, display equivalent levels of N-specific IgG antibodies as convalescents subjects. Regarding non-structural viral proteins, for the two viral proteins ORF3a and NSP8, IgG antibodies were produced in more than 50% of the convalescent subjects. Finally, a logistic regression model and a receiver operating characteristic (ROC) analysis show that combined detection of M and N proteins may be useful as a biomarker to differentiate breakthrough cases from vaccinated and convalescent individuals that did not receive prior vaccination. Taken together, these results suggest that multiple SARS-CoV-2 antigens may be used as differential biomarkers for distinguishing natural infection from vaccination.
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    Immune responses during COVID-19 breakthrough cases in vaccinated children and adolescents
    (Frontiers Media SA, 2024) Rivera Pérez, Daniela; Méndez Vejar, Constanza Soledad; Diethelm Varela, Benjamín Manuel; Melo González, Felipe Andrés; Vázquez Hernández, Yaneisi; Meng, Xing; Xin, Qianqian; Fasce, Rodrigo A.; Fernández, Jorge; Mora, Judith; Ramírez, Eugenio; Acevedo, Mónica L.; Valiente Echeverria, Fernando; Soto Rifo, Ricardo; Grifoni, Alba; Weiskopf, Daniela; Sette, Alessandro; Astudillo Paredes, Patricio Andrés; Le Corre Pérez, Monique Nicole; Abarca Villaseca, Katia; Perret Pérez, Cecilia; González Muñoz, Pablo Alberto; Soto Ramírez, Jorge Andrés; Bueno Ramírez, Susan; Kalergis, Alexis M.
    Background: Vaccine effectiveness against SARS-CoV-2 infection has been somewhat limited due to the widespread dissemination of the Omicron variant, its subvariants, and the immune response dynamics of the naturally infected with the virus. Methods: Twelve subjects between 3-17 years old (yo), vaccinated with two doses of CoronaVac®, were followed and diagnosed as breakthrough cases starting 14 days after receiving the second dose. Total IgGs against different SARS-CoV-2 proteins and the neutralizing capacity of these antibodies after infection were measured in plasma. The activation of CD4+ and CD8+ T cells was evaluated in peripheral blood mononuclear cells stimulated with peptides derived from the proteins from the wild-type (WT) virus and Omicron subvariants by flow cytometry, as well as different cytokines secretion by a Multiplex assay. Results: 2 to 8 weeks post-infection, compared to 4 weeks after 2nd dose of vaccine, there was a 146.5-fold increase in neutralizing antibody titers against Omicron and a 38.7-fold increase against WT SARS-CoV-2. Subjects showed an increase in total IgG levels against the S1, N, M, and NSP8 proteins of the WT virus. Activated CD4+ T cells showed a significant increase in response to the BA.2 subvariant (p<0.001). Finally, the secretion of IL-2 and IFN-γ cytokines showed a discreet decrease trend after infection in some subjects. Conclusion: SARS-CoV-2 infection in the pediatric population vaccinated with an inactivated SARS-CoV-2 vaccine produced an increase in neutralizing antibodies against Omicron and increased specific IgG antibodies for different SARS-CoV-2 proteins. CD4+ T cell activation was also increased, suggesting a conserved cellular response against the Omicron subvariants, whereas Th1-type cytokine secretion tended to decrease. Clinical Trial Registration: clinicaltrials.gov #NCT04992260