ABSTRACT
Purpose: The purpose of this study was to assess the clinical characteristics of serologic non-responders to COVID-19 booster vaccination in a cohort of solid organ transplant recipients. Method(s): All solid organ transplant recipients our center who received COVID-19 booster vaccination and had SARS-CoV-2 Spike IgG antibodies checked at least 4 weeks after the dose were included. We evaluated the patients who were found to have negative SARS-CoV-2 Spike IgG antibodies despite booster vaccination (i.e. serologic non-responders). Result(s): Among 657 solid organ transplant patients who had received a booster COVID-19 vaccination, 168 patients had Spike IgG antibodies checked during the study period. Forty-nine patients (29.2%) were found to be seronegative and were included in the analysis. 69% were male with a median age of 60 years. The majority of the cohort (47%) were kidney transplant recipients who had received primary vaccination series at a median of 206 days post-transplant. 65% had received basiliximab for induction immunosuppression. Most of the patients (65%) received primary vaccination with Pfizer COVID-19 vaccine and 67% received Pfizer COVID-19 booster vaccination at a median of 187 days after primary vaccination series. Spike IgG antibodies were checked at a median of 41 days from booster vaccination. No patients received rATG within 90 days of booster administration. Similarly, no patients received high dose (>250mg methylprednisolone equivalent) steroids within 30 days prior to booster vaccination. For immunosuppression, 27% were maintained on belatacept and 82% were on anti-metabolites at the time of the booster vacciantion. Ten patients (20%) experienced a COVID-19 infection postcompletion of their booster vaccination. Conclusion(s): In our solid organ transplant cohort, the majority of serologic nonresponders underwent basiliximab induction and were on an antimetabolite for maintenance immunosuppression. A limitation of our study was the use of different laboratory assays for determining IgG levels. Future work includes evaluating the clinical characteristics of COVID 19 booster serologic responders and comparing the two populations. (Table Presented).
ABSTRACT
Purpose: Evolving data suggests booster vaccine doses enhance the immunogenicity of SARS-CoV-2 vaccines in solid organ transplant recipients with higher IgG responses, neutralizing antibodies titers, and greater SARS-CoV-2-specific T-cell counts. Currently, there is no recommended framework for monitoring potential vaccine-related immunological graft injury. Here, we describe kinetics of dd-cfDNA pre- and post-booster vaccination in kidney transplant recipients (KTRs). Method(s): Electronic medical records were reviewed to identify KTRs that received a SARS-CoV-2 booster vaccine dose in 2021 and were monitored with dd-cfDNA pre- and post-vaccination. dd-cfDNA was collected as part of standard of care assessment. Pre-booster dd-cfDNA levels were defined as the most recent result prior to booster administration. Post-vaccination results were collected up to 30 days post-booster administration. Result(s): 116 KTRs were identified for analysis. Patient demographics are summarized in Table 1. Median time from transplant to SARS-CoV-2 booster administration was 463 days (IQR 333-787.25, Table 1). Pre-booster dd-cfDNA levels were established a median of 9 days (IQR 2.25 - 16) pre-booster. The median level of dd-cfDNA pre-booster was 0.17% (IQR 0.12% - 0.25%). There was no significant difference in median levels of dd-cfDNA up to 30 days post-booster administration (Kruskal Wallis test with multiple comparisons, all p values >0.99, Figure 1). No adverse clinical events or acute rejection episodes were reported within 30 days of SARS-CoV-2 booster administration in this cohort. Conclusion(s): Median dd-cfDNA levels were not impacted by SARS-CoV-2 booster administration, suggesting that patterns of subclinical injury that may potentiate inflammation, allosensitization or allograft rejection are unlikely in this setting. The stability of dd-cfDNA demonstrated here further reinforces the safety profile of SARS-CoV-2 vaccine booster administration in KTRs.
ABSTRACT
Background: Studies to date indicate that most adults develop IgG antibody to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) within 6 weeks of COVID-19 symptom onset. The seroconversion rate of solid organ transplant recipients (SOTR) following COVID-19 is unknown. Elucidation of humoral immune responses following COVID-19 in SOTR may inform risk of reinfection and the development of safe and effective vaccines for immunocompromised hosts. Methods: We assessed the frequency of SARS-CoV-2 IgG detection among adult SOTR diagnosed with COVID-19 by nasopharyngeal PCR assays between 3/1/2020 and 6/5/2020. SARS-CoV-2 IgG was detected in serum using the Abbott IgG assay at the manufacturer's recommended cut-off. Our primary objective was the frequency of SARS-CoV-2 IgG seropositivity after COVID-19. A secondary objective was to identify clinical factors associated with seroconversion. The mean age and nadir absolute lymphocyte count (ALC) were calculated between seropositive and negative SOTR and compared by Student's t-test. Results: Among 93 SOTR diagnosed with COVID-19, 19 died before SARSCoV- 2 IgG testing could be performed, and 18 had testing pending as of abstract submission. 56 SOTR (44 kidney, 5 heart, 4 liver, 1 lung, and 1 heart-kidney recipients) completed testing and were included in the analysis. Median age was 58 years (IQR 49.5-67), and all received maintenance immunosuppression at the time of COVID-19 diagnosis with median nadir ALC during illness of 400 (IQR 200-600). SARS-CoV-2 IgG testing was performed at a median of 60 days (IQR 50-70) from symptom onset, the shortest interval being 16 days. 47 out of 56 SOTR tested positive for SARS-CoV-2 IgG. The likelihood of seroconversion was not different between those who were tested at < or ≥ 60 days from symptom onset (p=0.26), nor did it vary significantly by age (p =0.59), gender (p=0.53) or nadir ALC (p =0.28). Conclusion: 83% of evaluated SOTR with COVID-19 disease had detectable SARS-CoV-2 IgG in serum at a median of 60 days after symptom onset. Studies are ongoing to identify variables associated with poor antibody response among the nearly 20% of SOTR in this cohort who failed to seroconvert. The significance of seroconversion on risk of reinfection and vaccine immunogenicity remains to be determined.