ABSTRACT
Lung transplant recipients (LTR) are susceptible to severe COVID-19 and had lower immune responses to primary SARS-CoV-2 vaccination as compared to the general population and to other solid organ transplant recipients. As immunity induced by booster vaccination and natural infection has increased since the beginning of the pandemic in the general population, immunity acquired by LTR is not well documented. Humoral and cellular immunity to SARS-CoV-2 was monitored in February and May 2023 in 30 LTR and compared to that of health care workers (HCW) and nursing home residents (NHR). LTR had significantly lower levels of SARS-CoV-2 binding and neutralizing antibodies and lower IFN-γ responses to Wuhan, Delta and XBB1.5 variants as compared to HCW and NHR. Humoral immunity decreased between the two visits whereas cellular immunity remained more stable. The persistent defect in SARS-CoV-2 immunity in LTR should encourage continued monitoring and preventive measures for this vulnerable population.
ABSTRACT
Introduction: Comorbidities and immunosuppressive therapies are associated with reduced immune responses to primary COVID-19 mRNA vaccination in kidney transplant recipients (KTRs). In healthy individuals, prior SARS-COV-2 infection is associated with increased vaccine responses, a phenotype called hybrid immunity. In this study, we explored the potential influence of immune suppression on hybrid immunity in KTRs. Methods: Eighty-two KTRs, including 59 SARS-CoV-2-naïve (naïve KTRs [N-KTRs]) and 23 SARS-CoV-2-experienced (experienced KTRs [E-KTRs]) patients, were prospectively studied and compared to 106 healthy controls (HCs), including 40 SARS-CoV-2-naïve (N-HCs) and 66 SARS-CoV-2-experienced (E-HCs) subjects. Polyfunctional antibody and T cell responses were measured following 2 doses of BNT162b2 mRNA vaccine. Associations between vaccine responses and clinical characteristics were studied by univariate and multivariate analyses. Results: In naïve KTRs, vaccine responses were markedly lower than in HCs and were correlated with older age, more recent transplantation, kidney retransplantation after graft failure, arterial hypertension, and treatment with mycophenolate mofetil (MMF). In contrast, vaccine responses of E-KTRs were similar to those of HCs and were associated with time between transplantation and vaccination, but not with the other risk factors associated with low vaccine responses in naïve KTRs. Conclusion: In conclusion, hybrid immunity overcomes immune suppression and provides potent humoral and cellular immunity to SARS-CoV-2 in KTRs.