SARS‐CoV‐2 vaccination in solid‐organ transplant recipients: What the clinician needs to know

Abstract

In response to the COVID-19 pandemic, SARS-CoV-2 vaccines have been developed at an unparalleled speed, with 14 SARS-CoV-2 vaccines currently authorized. Solid-organ transplant (SOT) recipients are at risk for developing a higher rate of COVID-19-related complications and therefore they are at priority for immunization against SARS-CoV-2. Preliminary data suggest that although SARS-CoV-2 vaccines are safe in SOT recipients (with similar rate of adverse events than in the general population), the antibody responses are decreased in this population. Risk factors for poor vaccine immunogenicity include older age, shorter time from transplantation, use of mycophenolate and belatacept, and worse allograft function. SOT recipients should continue to be advised to maintain hand hygiene, use of facemasks, and social distancing after SARS-CoV-2 vaccine. Vaccination of household contacts should be also prioritized. Although highly encouraged for research purposes, systematic assessment in clinical practice of humoral and cellular immune responses after SARS-CoV-2 vaccination is controversial, since correlation between immunological findings and clinical protection from severe COVID-19, and cutoffs for protection are currently unknown in SOT recipients. Alternative immunization schemes, including a booster dose, higher doses, and modulation of immunosuppression during vaccination, need to be assessed in the context of welldesigned clinical trials.

Antibody response to 2-dose SARS-CoV-2 mRNA vaccination in pediatric solid organ transplant recipients

“…In this observational cohort, 73.3% of pediatric SOTRs had a positive antibody response after receiving two doses of BNT162b2. Compared to adult SOTRs with reported seroconversation rates ranging from 5% to 58.8%, 5 these findings suggest that pediatric SOTRs may be able to mount more robust immune responses to SARS‐CoV‐2 vaccination. Similar to adult SOTRs, shorter time from transplantation, use of multiple immunosuppressive agents, and maintenance anti‐metabolite immunosuppression were associated with a negative antibody response 1,2 .…”

Head-to-Head Comparison of Response Rates to the Two mRNA SARS-CοV-2 Vaccines in a Large Cohort of Solid Organ Transplant (SOT) Recipients

“…The present study is, to the best of our knowledge, the largest study investigating antibody response rates and the safety of the two mRNA SARS-CoV-2 vaccines in SOT recipients [12,13]. Most importantly, we compared the immunogenicity of the two available mRNA vaccines.…”

Isolation of Functional SARS-CoV-2 Antigen-Specific T-Cells with Specific Viral Cytotoxic Activity for Adoptive Therapy of COVID-19

“…While the administration of mRNA vaccines has effectively reduced COVID-19-related severe disease, hospital admissions, and mortality in healthy adults [44][45][46], vaccine efficacy has not been as high in other target populations. In fact, different studies have reported lower rates of immune responses after vaccination in patients with hematologic pathologies (chronic lymphatic leukemia, multiple myeloma, lymphoma, and myeloproliferative malignancies) [47][48][49][50], as well as in solid organ transplant recipients [51][52][53][54].…”