ABSTRACT
Background: Approximately two years ago, COVID-19 was declared a global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and through genomic surveillance, we have seen the emergence of variants of SARS-CoV-2. In the United States, over 78 million cases and >900,000 deaths attributable to COVID-19 have been reported. SCD was identified as a risk factor for severe COVID-19 disease in adults and pediatric patients. The emergence of novel SARs- CoV-2 variants has led to challenges in diagnosis, treatment, and prediction of long-term sequelae in individuals with SCD and COVID-19. Aim(s): We compare the overall seasonal variation of COVID-19 variants and patterns of healthcare utilization and clinical presentation over time in pediatric patients with SCD and COVID-19 at Children's National Hospital (CNH). Method(s): Our single-center, observational cohort study included 193 pediatric patients with SCD (0-21 years) with PCR-confirmed SARSCoV- 2 infection between March 31, 2020, and January 31, 2022. Per the SECURE SCD Registry definitions, clinical severity was classified as asymptomatic, mild, moderate, and severe. Result(s): A total of 193 unique patients with SCD and positive SARS-CoV-2 PCRs between March 2020-January 2022 were included in our registry. Most patients were female (51.8%), and the mean age was 11.2 years (SD 6.5 years). Most of the cohort resides in Maryland (N=135), and HbSS was the dominant genotype (69.4%). During the alpha dominant variant of the COVID-19 pandemic (March 2020- June 2021) there were 70 cases, followed by 40 cases during the Delta variant (July 2021- December 19, 2021), and 83 cases during the Omicron variant dominance (from December 20, 2021-January 31,2022). There were 149 patients (77%) that presented to the emergency department (ED) or were hospitalized. There were a total of 80 hospitalizations (41.5%), and a relative comparison showed that the percentage of hospitalizations was highest during the delta wave (47.5%) and lowest during the omicron wave (36.1%) (p= 0.407). ED-only utilization was highest in the era of omicron (43.4%, N=36), followed by delta (32.5%, N=13), and then alpha (30%, N=21)(p=0.197). The most common SCD-related complication was vaso-occlusive (VOC) pain (33%, N=64) which accounted for half of all hospital admissions (51%, N=41 of 80). Acute chest syndrome (ACS) was reported in 40% (N=32) of admitted patients and was highest in the alpha era (54.8%, N=17). The use of blood transfusion therapy was highest in the alpha (N=17) and delta (N=14) variants, while Remdesivir use was highest in omicron (N=15). A total of 6 patients received monoclonal antibodies (Delta, N=4;omicron, N=2). Throughout all the variants, there was a significant difference in COVID-19 clinical severity (p>0.005). Of the patients classified as asymptomatic (13%, N=25), seventy-two percent (n=18) were diagnosed during the alpha variant. Mild severity was the most prevalent (69%, N=134), with the omicron variant having the highest cases (51.5%, N=69). Severe cases were observed in all variants (6.7%, N=13) but were most prevalent during the alpha variant (46.2%, N=6). Summary - Conclusion(s): Interestingly, while the relative percentage of hospitalizations was lowest during the omicron wave, it saw the highest percentages of ER utilization. Overall, COVID-19 remains mild in pediatric patients with SCD, and notably, there was higher health care utilization in the omicron era.