Abstract
Vaccine-induced SARS-CoV-2 antibody responses are attenuated in solid organ transplant recipients (SOTRs) and breakthrough infections are more common. Additional SARS-CoV-2 vaccine doses increase anti-spike IgG in some SOTRs, but it is uncertain whether neutralization of variants of concern (VOCs) is enhanced. We tested 47 SOTRs for clinical and research anti-spike IgG, pseudoneutralization (ACE2 blocking), and live-virus neutralization (nAb) against VOCs before and after a third SARS-CoV-2 vaccine dose (70% mRNA, 30% Ad26.COV2.S) with comparison to 15 healthy controls after two mRNA vaccine doses. We used correlation analysis to compare anti-spike IgG assays and focused on thresholds associated with neutralization. A third SARS-CoV-2 vaccine dose increased median total anti-spike (1.6-fold), pseudoneutralization against VOCs (2.5-fold vs. Delta), and neutralizing antibodies (1.4-fold against Delta). However, neutralization activity was significantly lower than healthy controls (p <.001); 32% of SOTRs had zero detectable nAb against Delta after third vaccination compared to 100% for controls. Correlation with nAb was seen at anti-spike IgG >4 Log10(AU/ml) on the Euroimmun ELISA and >4 Log10(AU/ml) on the MSD research assay. These findings highlight benefits of a third vaccine dose for some SOTRs and the need for alternative strategies to improve protection in a significant subset of this population.
Original language | English (US) |
---|---|
Pages (from-to) | 1253-1260 |
Number of pages | 8 |
Journal | American Journal of Transplantation |
Volume | 22 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2022 |
Keywords
- SARS-CoV-2/COVID-19
- basic (laboratory) research/science
- immunobiology
- infection and infectious agents – viral
- infectious disease
- solid organ transplantation
- translational research/science
- vaccine
ASJC Scopus subject areas
- Immunology and Allergy
- Transplantation
- Pharmacology (medical)