Clinical course and native antibody development after COVID-19 infection in 50 pediatric oncology patients.
Authors: Smart Maeve , Puopolo Olivia , Chang Matthew R , Ke Hanzhong , Marasco Wayne A , Marinac Catherine R. , Mack Jennifer W. , O'Neill Allison Frances , Janeway Katherine A. , Forrest Suzanne J. 
Published: June 2023

10063 Background: Pediatric oncology patients are at higher risk for severe COVID-19 infection compared to healthy children. However, pediatric cancer patients appear to be at lower risk of severe infection compared to adults with cancer. Lower rates of native antibody development have been seen in adults with hematologic malignancies particularly those with a history of transplant or anti-CD20 therapy. Data on the clinical characteristics of COVID-19 and antibody development after infection in children with cancer are limited. This study aims to describe the clinical manifestations of COVID-19 infection in pediatric caner patients, identify variables associated with severe infection, and evaluate native antibody development. Methods: REsearch on COVid-19 in Oncology to Inform Recovery and Mitigate Future Risk (RECOVOR) is an IRB approved institutional cohort study at Dana-Farber Cancer Institute. Pediatric patients with cancer who had COVID-19 are eligible 1-12 months following qtPCR confirmed infection. Blood samples are collected at 2 timepoints (3-12 months after COVID-19 infection and 6-9 months later) and undergo research analysis as well as clinical Anti-SARS-COV-2 (antibody response only to native infection) testing. Results: We report on the first 50 patients enrolled on the RECOVOR study from March 2021 to Dececember 2022 (COVID infection between March 2020 and November 2022). In this cohort, 56% (28/50) were male, 60% (30/50) had hematologic malignancies, 28% (14/50) had solid tumors, and 12% (6/50) had CNS tumors. Median patient age was 10.4 years (range 1-22 years). Most patients (86%; 43/50) were on active cancer treatment, of which 76% (33/43) had modifications in cancer-directed therapy due to COVID-19 infection. 76% of patients with COVID-19 were symptomatic and 26% (13/50) were hospitalized for COVID-19 symptoms. COVID-19 directed treatments were administered to 44% (22/50) of patients, most commonly antivirals (n = 12), monoclonal antibodies (n = 9), steroids (n = 3) and IVIG (n = 2). Native COVID-19 antibody testing 3-12 months post infection was performed for 88% (44/50) of patients, with 64% (28/44) seropositive at a median time of 5 months post-infection. Repeat antibody testing at timepoint 2 was available for 20 patients, with 14/14 remaining seropositive, 6/7 remaining seronegative, and 1 converting from seronegative to seropositive. Conclusions: The clinical characteristics of COVID-19 seen in this cohort of 50 pediatric oncology patients is consistent with prior reports, highlighting a high risk of hospitalization in this population. This study is the first to evaluate COVID-19 antibody development in pediatric cancer patients and showed that 63% of patients developed antibodies. Pediatric enrollment is ongoing and additional analyses are underway to assess factors associated with severe COVID-19 infection and/or associated antibody response.