Background Peru started its national vaccination campaign in February 2021 using Sinopharm vaccine, targeting healthcare personnel on its initial phase. Although the immunogenicity of this vaccine was tested in clinical trials, there are no studies that evaluated the humoral response post vaccination in Peru. Methods We conducted a cross sectional study, which objective was to evaluate the humoral immunogenicity triggered by the Sinopharm vaccine in Peruvian physicians. We collected demographic and epidemiologic data via an electronic. The SARS-CoV-2 spike protein S1/S2 antibodies were measured by chemiluminescense (Liaison®). A positive test was defined as >15 U/ml, which has correlation of 95% with neutralizing antibodies measured by plaque reduction neutralizing test. Results 92 participants were enrolled in the study. The epidemiologic characteristics are described in table 1. The mean level of antibodies measured at least 2 weeks from the second vaccine dose was 67.5 ± 70.5 U/ml. 85.7% of the study cohort had positive S1/S2 antibodies. In the univariate analysis, an imperfect negative correlation was found between the level of antibodies and participants’ age (r= -0.24; regression F test 5.25; p = 0.0242). A weak negative correlation was observed between the antibody titer and the time elapsed from the second vaccine dose and the day of antibody measurement (r= -0.17). A higher antibody level post vaccine was found in individuals who worked in COVID units (105.5 U / mL vs 58.2 U / mL; p = 0.0125), and in participants with history of COVID (216.5 U / mL vs 81.2 U / mL; p = < 0.0000). Hypertension was associated with lower antibody titers (36.9 U / mL vs. 74.6; p = 0.0464). In the multivariate analysis, working in COVID units, having previous COVID infection and shorter time from second vaccine dose and day of antibody measurement were associated with higher antibody levels post vaccine (table 2). Conclusion Our study showed that the time elapsed from the second vaccine dose and the day of antibody measurement, having previous COVID-19 infection and working in COVID -19 units may help to predict higher antibody titers post vaccine. Larger studies to evaluate the humoral response post Sinopharm vaccine and its clinical implications are still needed in Peru. Disclosures All Authors: No reported disclosures

La malnutrición por exceso en la infancia constituye una epidemia mundial y se asocia a múltiples enfermedades y complicaciones. Entre ellas, destacan los trastornos respiratorios del sueño (TRS), espectro de enfermedades que han emergido como un problema de salud relevante.Objetivo: Evaluar la relación entre la composición corporal y la presencia de TRS en escolares.Sujetos y Método: Estudio observacional analítico de corte transversal en 127 escolares de primero a octavo básico escogidos aleatoriamente de cinco establecimientos municipales de Valdivia, Chile. La incorporación al estudio ocurrió luego del proceso de consentimiento informado del responsable del escolar y asentimiento informado del menor. Se realizaron mediciones antropométricas y se determinó la presencia de TRS mediante el Pediatric Sleep Questionnaire (PSQ). Para el análisis se aplicó estadística descriptiva, t de Student y test χ2 para determinar asociación de variables con la presencia de TRS.Resultados: Destacó alta prevalencia de malnutrición por exceso (71,7%) y la obesidad alcanzó 39,4%. En tanto la prevalencia de TRS fue 32,3%. Hubo mayor proporción de niños con TRS en escolares obesos severos (56,3%), así como una media significativamente mayor en niños con TRS para los pliegues bicipital (14,6 mm ± 7,3 vs. 12,0 mm ± 6,6; p=0,002) y tricipital (19,8 ± 6,7 mm vs. 16,2 mm ± 6,0; p =0,04).Conclusiones: Existen altas prevalencias de malnutrición por exceso y TRS. De las medidas antropométricas, la presencia de TRS se asoció con mayor grosor de los pliegues bicipital y tricipital.