![]() ![]() These recommendations were based on limited evidence from individual studies on COVID-19 vaccines with small sample size and previous clinical experience with infections caused by other pathogens. On this basis, the European and US transplant guidelines consider that the benefits of COVID-19 vaccination may overweigh risks for patients receiving HSCT or CAR T-cell and recommend COVID-19 vaccination as early as three months after transplantation or cell therapy. Once infected with SARS-CoV-2, they are prone to developing severe or fatal symptoms, associated with higher rates of hospitalization and mortality. HSCT or CAR T-cell recipients are generally immunocompromised and vulnerable to infection post-transplantation due to underlying diseases, depletive conditioning regimens, multiple immunosuppressive treatments, or long-term application of immunosuppressants post-therapy. Globally, as of April 2022, five allogeneic CD19-directed CAR T-cell and two allogeneic B-cell maturation antigen (BMCA)-oriented CAR T-cell products have been approved for B-cell malignancies and multiple myeloma, respectively. For CAR T-cell therapy, either autologous or allogeneic T cells separated from peripheral blood are manufactured to target specific antigens and transfused back to patients after the ablative chemotherapy. Basically, HSCT involves depleting recipients’ dysfunctional hematopoietic and immune system and infusing autologous or allogeneic stem cells to achieve immune reconstitution, so-called autologous HSCT (auto-HSCT) or allogeneic HSCT (allo-HSCT), respectively. Hematopoietic stem cell transplantation (HSCT) and chimeric antigen receptor T cell (CAR T-cell) have been standard-of-care or emerging treatment options for multiple diseases, such as hematological malignancies and autoimmune diseases, which are featured by dysfunction of hematopoietic or immune system. However, the effectiveness and safety of COVID-19 vaccines in specific populations, such as immunosuppressed patients and patients with cancer, have not been well characterized, given that they were usually excluded from registrational clinical trials or defined as “warnings and precautions” groups in the labels. The COVID-19 vaccines have been validated in large-scale clinical trials and real-world settings to be protective and well-tolerable in general populations. In response, many countries have adopted mass COVID-19 vaccination and booster shot programs. According to the World Health Organization (WHO), as of July 15, 2022, the cumulative number of confirmed COVID-19 cases worldwide reached over 557 million and the cumulative number of deaths reached over 6.35 million. Since the outbreak of the human coronavirus disease 2019 (COVID-19), the pandemic has posed tremendous challenges to the globe, with many new variants emerging. Our findings may inform regular COVID-19 vaccination at appropriate intervals after HSCT or CAR T-cell therapy. This analysis revealed a diminished response to COVID-19 vaccines in HSCT or CAR T-cell recipients. Most vaccine-related adverse effects were mild and resolvable, comparable to general population. Other possible impact factors related to seropositivity were time interval between therapy and vaccination, use of immunosuppressive drugs and immune cell counts. The rates were comparable between autologous and allogeneic HSCT recipients. In subgroup analysis, CAR T-cell recipients exhibited an even lower seroconversion rate (one dose: 0.204 two doses: 0.277 ) than HSCT counterparts (one dose: 0.779 two doses: 0.793 ). The rates were significantly lower than those in healthy controls (nearly 100%). The pooled seropositivity rates in HSCT and CAR T-cell recipients were 0.624 for one dose, 0.745 for two doses. Random effects models were used to pool the rate of serologic response to COVID-19 vaccination in HSCT or CAR T-cell recipients and odds ratio comparing with healthy controls. The analysis included 27 observational studies with a total of 2899 patients receiving allogeneic HSCT (2506), autologous HSCT (286) or CAR T-cell therapy (107), and 683 healthy participants with serologic response data. Literature databases (MEDLINE, EMBASE, Web of Science, MedRvix and BioRvix) were searched for original studies with serologic response post COVID-19 vaccination in HSCT or CAR T-cell recipients published until July 14, 2022. The present meta-analysis evaluated the serologic response and safety of COVID-19 vaccines in these population. However, the effectiveness and safety of COVID-19 vaccines in these recipients is not well characterized. Patients receiving hematopoietic stem cell transplantation (HSCT) or chimeric antigen receptor T cell (CAR T-cell) therapy are immunocompromised and at high risk of viral infection, including SAR2-CoV-2 infection. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |