mRNA-1273 SARS-CoV-2 vaccine safety and COVID-19 risk perception in recently transplanted allogeneic hematopoietic stem cell transplant recipients

PURPOSE: This study aims to describe the incidence and severity of adverse events (AEs) following the mRNA-1273 SARS-CoV-2 vaccine and explore the risk perception of COVID-19 in allogeneic hematopoietic stem cell transplant (HCT) recipients. METHODS: We performed a single-center prospective study including recently transplanted (< 2 years post-infusion) allogeneic HCT recipients. AEs were assessed through phone calls and graded from 0 to 4, while COVID-19 risk perception was measured using the Brief Illness Perception Questionnaire (BIP-Q5). RESULTS: Fifty-four HCT recipients were evaluated. Incidence and grades of AE (94.4% and 85.2% after the first and second dose, respectively) were similar to those described in the general population. The most common AE was pain at the site of injection. Three patients (5.6%) developed a grade ≥ 3 AE. Vaccine-related cytopenias and graft-versus-host disease flares were not observed. Female sex (OR 3.94, 95% CI 1.14–13.58, p = 0.03) and time since HCT (per month since HCT: OR 1.09, 95% CI 1.01–1.18, p = 0.04) were associated with the occurrence of any AE. The patients’ risk perception level of COVID-19 decreased over time (p < 0.05). CONCLUSION: Our study confirms that the mRNA-1273 SARS-CoV-2 vaccine is safe in recent HCT recipients and suggests that the perceived risk of COVID-19 decreases over time.