Seroprevalence of SARS‐CoV‐2 in pediatric hematology‐oncology patients

Abstract

BackgroundThe COVID‐19 pandemic disproportionately affected persons with underlying medical conditions. SARS‐CoV‐2 infection susceptibility and vaccine effectiveness in pediatric hematology‐oncology patients were unknown.MethodsFrom February to July 2022, anti‐spike and anti‐nucleocapsid Ig were assayed in 354 pediatric hematology‐oncology subjects, including 53 oncology patients receiving chemotherapy (cancer), 150 patients with sickle cell disease (SCD), and 151 benign consult and long‐term follow‐up patients (controls). Participants completed a questionnaire.ResultsFrequencies of COVID‐19 infection, defined by positive PCR/antigen test or anti‐nucleocapsid Ig, were 62% in cancer, 71% in SCD, 52% in controls, with SCD statistically different than controls (p = .001). Infection was associated with COVID‐19 exposure, Hispanic/Latino or Black/African American ethnicity, multi‐family dwelling, sports participation; COVID‐19 booster decreased association with infection. In COVID‐19‐positive cancer patients, 58% had positive anti‐nucleocapsid and 76% had positive anti‐spike (≥10 U/mL), compared to essentially 100% seroconversion in SCD and controls (p < .0001, p = .01, respectively). Infection led to high anti‐spike (≥2500 U/mL) in 12% cancer, 14% SCD, and 15% controls (p = .93). Vaccination resulted in anti‐spike positivity in 90% cancer, 100% SCD, and 100% controls (p = .06), and in high anti‐spike in 20% cancer, 47% SCD, and 41% controls (p = .36). Of boosted subjects, one of two cancer, 6/6 SCD, and 19/19 controls exhibited high anti‐spike.ConclusionsCancer patients demonstrated similar SARS‐CoV‐2 infection frequency as controls, but diminished antibody response to infection and vaccination. SCD patients exhibited seroconversion indistinguishable from controls. Vaccination was associated with higher frequency of high anti‐spike than infection; vaccination plus booster was most effective in eliciting high anti‐spike antibody detectable beyond 90 days.