Korean J Transplant.  2022 Nov;36(Supple 1):S16. 10.4285/ATW2022.F-0936.

Comparison of humoral immunogenicity in solid organ transplant recipients after third-dose mRNA vaccine with homologous or heterologous schedules: an observational study

Affiliations
  • 1Department of Pediatrics, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
  • 2Department of Surgery, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
  • 3Division of Biostatistics, Department of Biomedical Systems Informatics, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea

Abstract

Background
Solid organ transplant recipients (SOTRs) are susceptible to severe coronavirus disease 2019 (COVID-19) and im-munogenicity studies of Omicron variants according to vaccination schedules are lacking. We examined the humoral immuno-genicity following third-dose mRNA vaccine administration in Korean SOTRs who received primary COVID-19 vaccine series on a homologous or heterologous schedule.
Methods
We recruited SOTRs at the Severance Hospital from October 27, 2021, to March 31, 2022. Blood samples were col-lected between 14 days and 5 months after the second and third mRNA vaccine (BNT162b2 or mRNA-1273) doses. The SARSCoV-2 anti-spike IgG titer was analyzed using an enzyme-linked immunosorbent assay (cut-off <7.1 BAU/mL), and the neutral-ization inhibition rate was analyzed using the surrogate neutralization assay (cut-off <30% of inhibition) for the wild-type, Delta, and Omicron variants.
Results
Overall, 148 participants were included. About 30% participants (n=45) received ChAdOx1/BNT162b2/BNT162b2, 24% (n=36) ChAdOx1 nCoV-19/ChAdOx1 nCoV-19/BNT162b2, 22% (n=33) BNT162b2/BNT162b2/BNT162b2, 20% (n=29) ChAdOx1/ ChAdOx1/mRNA-1273, and 3% (n=5) received other regimens. No significant differences existed in the SARS-CoV-2 anti-spike IgG positivity rate obtained between the homologous BNT162b2/BNT162b2/BNT162b2 (85%) and the other heterologous groups (83% of ChAdOx1/ChAdOx1/BNT162b2, 90% of ChAdOx1/ChAdOx1/mRNA-1273, and 78% of ChAdOx1/BNT162b2/BNT162b2). There was no significant difference in the neutralization inhibition rate between the four groups for wild-type, Delta, and Omicron variants. The median neutralization inhibition rates against Omicron were 25%, significantly lower than those against wild-type (87%–97%) and Delta (55%–89%) (P<0.001).
Conclusions
Heterologous COVID-19 vaccinations, comprising a third-dose mRNA vaccine, showed similar humoral immunoge-nicity compared to homologous BNT162b2/BNT162b2/BNT162b2. Regardless of the schedule, the neutralization inhibition rate against Omicron was very low; therefore, additional preventive measures are required in such high-risk populations.

Full Text Links
  • KJT
Actions
Cited
CITED
export Copy
Close
Share
  • Twitter
  • Facebook
Similar articles
Copyright © 2024 by Korean Association of Medical Journal Editors. All rights reserved.     E-mail: koreamed@kamje.or.kr