COVID-19 vaccine and hematopoietic stem cell transplantation

In the pandemic era of coronavirus disease 2019 (COVID-19), vaccines have been developed and approved to control the pandemic that might reduce the COVID-19 mortality. Transplant recipients are among the high-risk groups and are more susceptible to COVID-19 infection. According to the available data about COVID-19 vaccines, some platform technologies include vector-based, inactivated, protein subunit, virus-like particles, mRNA, and DNA vaccines (1). There are several guidelines about vaccination in immunocompromised individuals for both non-live- and live vaccines. However, there are still limited evidence-based data about COVID-19 vaccines in the hematopoietic stem cell transplantation (HSCT), and establishing a proper recommendation for vaccination in these patients would be challenging (2, 3). Transplant recipients may have shown lesser responses to the vaccines compared with the general population, and it is unknown to what extent the vaccine is effective in this group of patients. Also, in many countries, the vaccination schedule is not adjustable by the patients or physicians, and selecting a particular time window for the best efficacy of immunization is impossible. In this regard, the main concern in the patients treated with immunosuppressive drugs is not worsening symptoms and disease following vaccination. The most critical issue is determining the best time for vaccination to increase its efficacy. Here are some considerations about vector-based, inactivated, and mRNA- nanoparticle vaccines, but most evidence is not based on the results of cohort or clinical trial studies. Before HSCT, patients could receive the COVID-19 vaccine if they are not already immunosuppressed. According to evidence about other inactivated vaccines, such as the influenza vaccine, the interval to start the conditioning regimen could be considered 2 - 4 weeks following the vaccination (4). In autologous HSCT patients, COVID-19 vaccination can be considered 1 - 3 months after transplantation if there has been a community outbreak. If acquiring or transmitting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was well controlled, vaccination could be withheld after six months of transplantation. In the current pandemic, COVID-19 vaccination in allogeneic HSCT patients could be considered at least three months after transplantation. If transmission of SARS-CoV-2 was controlled, vaccination could be withheld after six months of transplantation (4-6). Vaccination of patients with chronic graft versus host disease (cGVHD) receiving less than 20 mg/day prednisolone (or equivalent) for less than 2 weeks, can be considered similar to the HSCT recipients with no GVHD (5). Vaccines in HSCT recipients with active SARS-CoV-2 infection are not effective thus, receiving the vaccine is not recommended. If an HSCT recipient has received the COVID-19 vaccine before HSCT, re-vaccination after transplantation is suggested (6). The administration of the vaccine is considered when the immune system acquired functional competence. Transplant donation should not be delayed due to the vaccination of the donor to protect the patients in case the transplant is urgent (6). It was reported that recipients who have received anti-B cell antibodies might get the vaccine at 3 - 6 months after the administration and four weeks before the next course of B cell-depleting therapy. If this time window was not possible, vaccination can be regarded under B-cell depleting therapy, considering a suboptimal response to the vaccine (7). It should be noted that the effects of rituximab may last for six months or even a year. Also, the decision to order vaccines following the use of rituximab should be based on the level of immunoglobulins and CD19. There is no strong evidence for the short duration of vaccination following the use of rituximab (such as 3 to 6 months). However, despite the low efficacy of the vaccine in such conditions, it is recommended to get the vaccine whenever available. It is reasonable that recipients who have received therapy with antithy

The effect of vitamin E and vitamin C in patients with COVID-19 pneumonia;a randomized controlled clinical trial

Introduction: Cytokine storm and oxidative stress play a key role in the pathogenesis of coronavirus disease 2019 (COVID-19). Vitamins C and E are two known antioxidants with possible theoretical beneficial effects in COVID-19 patients. Objectives: This study aimed to clinically evaluate the effects of the combination of these agents as adjunctive therapy with the standard treatment in the outcome of COVID-19 patients. Patients and Methods: Hospitalized non-severe COVID-19 patients were randomly divided into two groups of intervention (n=38) and control (n=34) to receive either oral vitamin C 1000 mg daily plus oral vitamin E 400 IU daily in addition to the national standard treatment regimen (hydroxychloroquine) or standard regimen alone, respectively, during the hospitalization period until hospital discharge or ICU admission. The clinical response of patients at the end of treatment (either cure, improvement, or failure), the duration of hospitalization, and the mortality rate were recorded and compared between the groups. Results: During the study, three patients in the intervention group (7.89%) and five patients in the control group (14.71%) had treatment failure, while all other patients had clinical improvement (P = 0.380). The duration of hospitalization was shorter in the intervention group (7.95 +/- 3.18 days) compared to the control group (8.03 +/- 2.83 days);however, the difference was not statistically significant (P = 0.821). Furthermore, no patients in both groups died during the study. Conclusion: The combination of oral vitamins C (1000 mg daily) and E (400 IU daily) has no beneficial effect in COVID-19 patients.