P-525. Severe Pediatric COVID-19 During the Predominance of the Lambda Variant at a Referral Hospital in Lima, Peru, 2020–2022

Abstract Background Lambda (C.37) was a variant originally identified in Peru, its impact on severe COVID-19 disease in children has not been adequately studied in Andean countries. Thus, this study aims to evaluate the risk of severe COVID-19 in hospitalized children during the predominance of the Lambda variant at a referral hospital in Lima, Peru.Figure 1.Cases of hospitalized children across periods of SARS-CoV-2 variant predominance a at Hospital Nacional Edgardo Rebagliati Martins in Lima, Peru, 2020–2022 (N=240).a. The type of SARS-CoV-2 predominance was defined as the period in which a variant was dominant (more than 70%) in Peru, according to CDC Peru and GISAID Data Science Initiative.Table 1.Clinical characteristics of hospitalized children with SARS-CoV-2 infection in Lima, Peru, 2020–2022.IQR: Interquartile range; ICU: Intensive care unit.a. Kruskal-Wallis test.b. Chi-square test.c. Fisher's exact t-test. Methods Retrospective cohort of patients 14 years hospitalized at Hospital Nacional Edgardo Rebagliati Martins, from April 2020 to April 2022. The type of SARS-CoV-2 predominance was defined as the period in which a variant was dominant (more than 70%) in Peru, according to CDC Peru and GISAID Data Science Initiative. Severe COVID-19 was defined if any of the following criteria was present: admission to the intensive care unit, use of vasopressors/inotropes, need for high-flow nasal cannula (HFNC) therapy, requirement for invasive mechanical ventilation, or death. Crude and adjusted relative risk with 95%CI were calculated using generalized linear models with a Poisson family, log link, and robust variance.Table 2.SARS-CoV-2 variants and severe COVID-19 in hospitalized children in Lima, Peru, 2020–2022 (N=240).ICU: Intensive care unit; RR: Relative risk; CI: Confidence Interval; NC: Not calculable.a. Not calculable because there is a zero value in one cell. Results 240 children were included; 18% were admitted during the period of Lambda variant predominance, median age was 89.5 months, and 54.2% with comorbidities. Severe COVID-19 occurred in 14.17%. No severe COVID-19 cases were reported during the Delta predominance, whereas 25.28% of children experienced severe disease during the Lambda predominance, with a higher use of HFNC (16.28%) compared to other variant predominance periods (p=0.031). However, the hospitalization during Lambda predominance was not associated with severe disease (RR 1.41, 95%CI:0.67–2.98; p=0.367), nor was it associated with other critical outcomes when compared to the Wuhan predominance period, adjusted for the Omicron predominance, age, male sex, and comorbidities. Conclusion In our cohort, hospitalization during the Lambda predominance was probably not associated with greater severity of COVID-19 disease. Large multicenter studies are needed to confirm our findings. Disclosures All Authors: No reported disclosures