SARS-CoV-2 vaccination in cardiothoracic organ transplant recipients: effective strategies wanted

Abstract

Since end of 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread from Wuhan, China to the rest of the world, leading to more than 160 million confirmed cases of coronavirus disease 2019 (COVID-19) with more than 3.3 million deaths worldwide [1]. COVID19 results in a spectrum of clinical manifestations ranging from asymptomatic to critical illness including acute respiratory distress syndrome (ARDS) and multiorgan failure, which are associated with high morbidity and mortality. Factors that increase risk for an adverse disease course include older age and the presence of comorbidities such as diabetes, hypertension, chronic kidney disease, morbid obesity, coronary heart disease, and chronic lung disease [2]. Solid organ transplant (SOT) patients are considered to be at high risk for complications from COVID-19 because of the high prevalence of the comorbidities that have been established as risk factors for severe disease, as well as a higher risk of infection due to their immunosuppressed status [3, 4]. Current data on the clinical course of COVID-19 in immunocompromised patients are limited. Vaccination against COVID-19 may be an effective intervention in fighting the pandemic. Several SARS-CoV-2 vaccines have been approved for administration in various countries and are available to select populations based on local recommendations and regulations. Current efficacy data from randomized clinical trials in immunocompetent recipients are variable as noted in Table 1, but thus far consistently demonstrate close to 100% protection against severe COVID-19-related intensive care hospitalization or death [5]. Observational “real-world” findings from Israel, including 596,618 vaccinated persons matched to unvaccinated controls, demonstrated an 87% reduction in COVID-19-related hospitalization following administration of two doses of the Pfizer-BioNTech vaccine [6]. Safety and efficacy data for SARS-CoV-2 vaccines in transplant recipients are limited thus far, as transplant recipients were not included in the already published randomized vaccine trials [5]. However, guidelines regarding COVID-19 vaccination in patients with thoracic transplantation have been released by the International Society for Heart and Lung Transplantation (ISHLT) and the American Society for Transplantation (AST) in a combined statement [7], as well as by the European Society of Cardiology (ESC) [8], unequivocally recommending vaccination at least 1 month after transplant surgery. In this issue of the Journal, Schramm and colleagues [9] report on a prospective cohort study of the immune response after administration of the BNT162b2 vaccine in 50 cardiothoracic (heart (n = 42), lung (n = 7) or heart–lung (n = 1)) transplant recipients from 5 German transplant centers 10–36 months after transplantation, compared to 50 healthy staff members similarly immunized with the same messenger RNA (mRNA) vaccine. Antibody titers, functional inhibitory capacity of neutralizing antibodies, and T-cell response (interferon-γ release) were measured via three separate tests. Forty-six (92%) of the transplant recipients did not show any humoral or T-cell response 21 days after completion * Sebastian Ewen [email protected]