Disease severity associated with RSV in pediatric hemato-oncology patients–the role of RSV vaccine

Abstract Background RSV vaccine was recently introduced, and is recommended for infants and immunosuppressed children. Viral respiratory infections may pose a significant risk for pediatric cancer patients and lead to delay in chemotherapy, prolonged illness, hospitalization, and mortality. Limited data exist on predictive factors for adverse clinical outcomes. This study aims to describe associations between the existence of RSV and severe outcomes among children with hematologic cancer. Methods A retrospective cohort study among pediatric cancer patients treated in the Pediatric Hematology-Oncology Department at Rambam Health Care Campus from 2016 to 2022. Patients with a positive rt-PCR test for one of the following viruses: Respiratory Syncytial Virus (RSV), Adenovirus, Human Metapneumovirus (HMPV), SARS-CoV-2, Parainfluenza, or Influenza were included. Demographic, clinical, and laboratory data were collected for each case. Logistic regression was conducted to assess the association between independent variables and severe outcomes (admission to pediatric intensive care unit, hospitalization above seven days, co-bacterial infections, and 30 days mortality). Results A total of 366 viral infections episodes were identified among 238 patients, with a median age at presentation of 5.15 years. Hematological malignancies were diagnosed in 187 patients (51%), solid tumors in 113 patients (31%), and 66 patients (18%) had undergone bone marrow transplantation. There were 65 events of RSV (18%). A total of 38 severe events was recorded. One patient died within 30 days of infection with RSV. Among the subgroup of hematological malignancies, RSV was positively associated with severe outcomes (OR = 4.08, p = 0.048), adjusted for demographic and clinical variables. Conclusions This study identifies RSV infection in association with severe outcomes among hematological pediatric cancer patients. This emphasizes the importance of RSV vaccination in immunocompromised pediatric patients. Key messages • RSV among hemato-oncology pediatric patients is a strong risk factor for severe outcomes. • Complying with the RSV vaccine recommendations for immunosuppressed children is of a major importance.