mRNA-1273 SARS-CoV-2 vaccine in recently transplanted allogeneic hematopoietic cell transplant recipients: Dynamics of cellular and humoral immune responses and booster effect.

Allogeneic hematopoietic stem cell transplant (HCT) recipients are at high risk of severe COVID-19 despite vaccination. Little is known about cellular response to SARS-CoV-2 vaccine in this population, especially in recently transplanted patients (RTP). In this single-center study we examined cellular and humoral response to the mRNA-1273 (Spikevax®) vaccine in recently transplanted patients (RTP, n = 49), and compared them to long-term transplanted patients (LTTP, n = 19) and healthy controls (n = 20) at three different timepoints: one and three months after the second dose (T1 and T2, respectively, 28 days apart), and one month after the third dose (T3). Controls did not receive a third dose. RTPs showed lower IgG anti-S1 titers than healthy controls at both T1 (mean 0.50 vs 0.94 arbitrary units -AU-, p < 0.0001) and T2 (0.37 vs 0.79 AU, p < 0.0001). They also presented lower titers than LTTPs at T1 (0.50 vs 0.66, p = 0.01), but no differences at T2 (0.37 vs 0.40 AU, p = 0.55). The rate of positive T-cell responses was lower in RTPs than in controls at both T1 and T2 (61.2 % vs 95 %, p = 0.007; 59.2 % vs 100 %, p = 0.001, respectively), but without statistically significant differences between transplanted groups. At T3 no differences were seen between RTPs and LTTPs as well, neither in IgG antibodies (p = 0.82) nor in cellular responses (p = 0.15), although a third dose increased the rate of positive cellular and humoral responses in approximately 50 % of recently transplanted patients. However, active immunosuppressive treatment severely diminished their chances to produce an adequate response.

Feasibility of a New Model of Care for Allogeneic Stem Cell Transplantation Recipients Facilitated by eHealth: The MY-Medula Pilot Study.

The use of allogeneic stem cell transplantation (allo-SCT) for the treatment of hematologic diseases is steadily increasing; however, allo-SCT has the downside of causing considerable treatment-related morbidity and mortality. Mobile technology applied to healthcare (mHealth) has proven to be a cost-effective strategy to improve care and offer new services to people with multimorbidity, but there are little data on its usefulness in allo-SCT recipients. Here we describe a new integrated healthcare model facilitated by an mHealth platform, EMMASalud-MY-Medula, and to report the results of a feasibility and usability pilot study. The MY-Medula platform was developed in 4 phases. First, patient and healthcare professional needs were identified, and technological development and pretesting tests were conducted (phases 1 to 3, January 2016 to March 2021). Then a nonrandomized, prospective, observational, single-center pilot study was conducted (October 2021 to January 2022) at the adult SCT unit of a tertiary university hospital. Twenty-eight volunteer allo-SCT recipients were included in the pilot study, of whom one-half were outpatients in the first-year post-SCT and one-half were affected by steroid-dependent graft-versus-host disease (SR-GVHD). All patients used the MY-Medula app during the 2-month follow-up period, with a median number of visits to the app of 143 (range, 6 to 477). A total of 2067 self-monitoring records were created, and 205 text messages were received, most of them related to symptoms description (47%) and doubts about medication (21%). In 3.4% of the cases, drug dosage was adjusted by the pharmacist because of dosing errors or interactions. At the end of the study, a 6-question Likert-type questionnaire for patients and a 22-question test for healthcare professionals showed a high degree of satisfaction (95% and 100%, respectively) with the new healthcare pathway. Reengineering the follow-up of allo-SCT recipients into an integrated, multidisciplinary model of care facilitated by mHealth tools is feasible and has been associated with high usability and a high degree of satisfaction by patients and healthcare professionals. A randomized trial aiming to determine the cost-effectiveness of MY-Medula-based follow-up post-SCT is currently enrolling participants.

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.