Risk of COVID-19 Infection in Long-term Survivors of Blood or Marrow Transplantation: A BMTSS Report.

There is limited information regarding COVID-19 in long-term blood or marrow transplant (BMT) survivors. We leveraged the BMT Survivor Study (BMTSS) to address this gap. BMTSS included patients who underwent BMT at one of three US sites between 1974 and 2014 and survived ≥2 years after BMT. A sibling cohort serves as a non-BMT comparison group. Participants (2,430 BMT survivors; 780 non-BMT participants) completed the BMTSS survey between 10/2020 and 11/2021 about COVID-19 testing, risk mitigation behaviors, morbidity, and healthcare utilization. Median age at BMT was 46 years (range: 0-78 years) and median follow up since BMT was 14 years (6-46 years); 76% were non-Hispanic white, 54% had received allogeneic BMT. The risk of COVID-19 infection was comparable for BMT survivors vs non-BMT participants (15-month cumulative incidence: 6.5% vs. 8.1%; adjusted odd ratio [aOR]=0.93, 95%CI=0.65-1.33, p=0.68). Among survivors, being unemployed (aOR=1.90, 95%CI=1.12-3.23, p=0.02; reference: retired) increased the odds of infection; always wearing a mask in public was protective (aOR=0.49, 95%CI=0.31-0.77. p=0.002; reference: not always masking). When compared with COVID positive non-BMT participants, COVID positive BMT survivors had higher odds of hospitalization (aOR=2.23, 95%CI=0.99-5.05, p=0.05); however, the odds of emergency department visits were comparable (aOR=1.60, 95%CI=0.71-3.58, p=0.25). COVID-19 infection status did not increase the odds of hospitalization among BMT survivors (aOR=1.32, 95%CI=0.89-1.95, p=0.17, but did increase the odds of ED visits (aOR=2.63, 95%CI=1.74-3.98, p=<0.0001). These findings inform healthcare providers about the management of long-term BMT survivors during the ongoing pandemic.