Korean J Transplant.  2022 Nov;36(Supple 1):S360. 10.4285/ATW2022.F-5005.

Decreased immunogenicity after SARS-CoV-2 vaccination in liver and kidney transplant recipients

• Kwon JH
• Kim HW
• An JN
• Kim SG
• Kim YK
• Moon SM
• Jang B

• KMID: 2535244
• DOI: http://doi.org/10.4285/ATW2022.F-5005

Abstract

Background
Recently published studies have found an impaired immune response after SARS-CoV-2 vaccination in solid organ recipients. However, most of these studies have not assessed immune cellular responses in solid organ transplant recipients. In this study, a prospective double-arm cohort study was performed to evaluate the humoral and cellular immune response to SARS-CoV-2 vaccination in solid organ transplant recipients compared to healthy staff members with the normal function of the immune system.
Methods
A total of 64 transplant patients and an age-matched control group of 103 healthy staff members were included. Blood samples were obtained and analyzed after the second dose and the boosting (third) dose, respectively. For evaluation of the vi-rus-neutralization capacity of each group, serum was analyzed using a surrogate SARS-CoV-2 neutralization test to quantify the functional inhibitory capacity of neutralizing antibodies (Genscript) against SARS-CoV-2 spike protein. Inhibition scores of under 30% were considered negative.
Results
Except for the vaccination subgroup of initial two dosages of AstraZeneca followed by Pfizer was significantly higher in the healthy control group, other prime-booster combination subgroup proportion was similar between the group. After the stan- dard two doses of vaccination, only 28.3% of the transplant recipients demonstrated positive functional inhibition of neutralizing antibodies, significantly lower than 70.9% of the healthy control group (P<0.001). Even after the booster (third) dose of vaccina-tion, 43.2% of the transplant recipients showed positive functional inhibition of neutralizing antibodies, significantly lower than 100% of the healthy control group (P<0.001). No other immune-associated complications such as acute rejection occurred after SARS-CoV-2 vaccination in the transplant recipient group.
Conclusions
Our data strongly suggest revised vaccination approaches in immunocompromised patients, including individual immune monitoring for the protection of this vulnerable group at risk of developing severe COVID-19. It urges a review of future vaccine strategies for these patients.