ABSTRACT
The high morbimortality due to SARS-CoV-2 infection in oncohematological diseases (OHD) and hematopoietic stem cell transplant (HSCT) recipients in the pre-vaccine era has made vaccination a priority in this group. After HSCT, the immune responses against common vaccines such as tetanus, varicella, rubella, and polio may be lost. However, the loss of immunity developed by COVID-19 vaccination after HSCT has not been completely defined. In this study, both humoral and cellular immunity against SARS-CoV-2 were analyzed in 29 individuals with OHD who were vaccinated before receiving allogeneic (n = 11) or autologous (n = 18) HSCT. All participants had low but protective levels of neutralizing IgGs against SARS-CoV-2 after HSCT despite B-cell lymphopenia and immaturity. Although antibody-dependent cellular cytotoxicity was impaired, direct cellular cytotoxicity was similar to healthy donors in participants with autologous-HSCT, in contrast to individuals with allogeneic-HSCT, which severely deteriorated. No significant changes were observed in the immune response before and after HSCT. During follow-up, all reported post-HSCT SARS-CoV-2 infections were mild. This data emphasizes that COVID-19 vaccination is effective, necessary, and safe for individuals with OHD and also supports the persistence of some degree of immune protection after HSCT, at least in the short term, when patients cannot yet be revaccinated.
ABSTRACT
BACKGROUND: The COVID-19 pandemic has caused major disruption to health systems, with allogeneic haemopoietic cell transplant (alloHCT) services a particularly vulnerable area. Ongoing provision of alloHCT has required dynamic responses at national and local levels. In Australia and New Zealand (ANZ), a high reliance on unrelated donors from overseas registries has posed an additional challenge. AIMS: To describe the impact of COVID-19 on alloHCT services in ANZ in the first year of the pandemic. METHODS: Data from the national alloHCT patient and unrelated donor registries were extracted for a 2-year time frame. Comparisons were made between a pre-pandemic period of 1 March 2019 to 29 February 2020 and the corresponding dates during the pandemic, 1 March 2020 to 28 February 2021. RESULTS: There was a 13% decrease in the number of allogeneic transplants, a reversal of steady increases in previous years, with the largest decrease in unrelated donor transplants. Local donors supplied a greater proportion of unrelated stem cell products. With a switch to universal cryopreservation, the time from request of a product to infusion increased by a median of 25.5 days for overseas products and 14 days for local products. There was a significant increase in the number of products collected but not used. CONCLUSIONS: A strong public health response and coordinated transplant community activities allowed for safe provision of alloHCT in ANZ; however, our data suggest that the timely delivery of allogeneic transplants was affected by the COVID-19 pandemic. Continued dedicated efforts are required to minimise further impacts.
ABSTRACT
This is the first report of a case of COVID-19 after allogeneic stem cell transplantation. Our case suggests that COVID-19 may exist without characteristic CT images, especially in immunocompromised hosts, such as patients after transplantation.