Transplant Patients Risk for SARS-CoV-2 Infection Post-2nd Vaccine Dose; We Are Not Home and Dry Yet
1Cardiff Transplant Unit, University Hospital of Wales, Cardiff, United Kingdom, 2Cardiff Transplant Unit, University Hosptal of Wales, Cardiff, United Kingdom
Meeting: 2022 American Transplant Congress
Abstract number: 1640
Keywords: Antibodies, COVID-19, Infection, Vaccination
Topic: Clinical Science » Infection Disease » 24 - All Infections (Excluding Kidney & Viral Hepatitis)
Session Information
Session Name: All Infections (Excluding Kidney & Viral Hepatitis) IV
Session Type: Poster Abstract
Date: Tuesday, June 7, 2022
Session Time: 7:00pm-8:00pm
Presentation Time: 7:00pm-8:00pm
Location: Hynes Halls C & D
*Purpose: SARS-CoV-2 is associated with high mortality among transplant recipients. Data of transplant patients’ infections post-2nd vaccine dose is not available. The aim of the study was to establish the extend to which vaccinated patients were protected from severe infection.
*Methods: We recruited 920 kidney transplant patients receiving at least one dose of SARS-CoV-2 vaccine (Astra-Zeneca-AZ or Pfizer) excluding patients with known virus pre-exposure. Serological status was determined using the COVID-SeroKlir enzyme-linked-immunosorbent-assay (ELISA) (Kantaro-EKF). Patients with corrected antibody level less than 0.7AU/mL were considered seronegative. All SARS-CoV-2 infections post-2nd and up to 2-weeks post the third dose were recorded. We considered severe the infections requiring admission and moderate the infections lasting over 10 days or requiring A&E (ER) attendance without admission.
*Results: 593 patients had their samples analysed post-second dose. 42.8% of AZ patients seroconverted (148/346) compared to 52.6% of Pfizer (130/247, p=0.02, HR 1.07-2.06). There were 53 PCR-confirmed infections between 1/7/21 and 20/11/21, 33 in AZ and 18 in Pfizer patients. Two patients had received no vaccine and 3 patients who received AZ had no specimen for analysis. 10 patients’ infection was over 6 months post-2nd dose.41/315 (13%) of seronegative patients got infected compared to 7/278 (2.5%) of seropositive patients (p=0.00001, OR 5.9 CI 2.554-13.139) during this period.There were 15 mild, 5 moderate, and 13 severe infections post AZ and 11 mild, 3 moderate, 4 severe post Pfizer respectively. 16/17 patients admitted and 7/8 with moderate disease had no demonstrable antibody response at their latest sample post-2nd vaccine dose. There were 2 deaths. We observed at least 3 seropositive patients who became seronegative and got infection.
*Conclusions: 5.5% of vaccinated and 13% of seronegative transplant patients got SARS-CoV-2 infection following the 2nd vaccine dose. 92% of patients with moderate/severe disease were seronegative. A significant proportion of transplant patients remains at risk of serious illness due to SARS-CoV-2 because they do not demonstrate an antibody response to vaccination.
To cite this abstract in AMA style:
Koimtzis G, Szabó L, Nagaraja P, Chalklin C, Elker D, Asderakis A. Transplant Patients Risk for SARS-CoV-2 Infection Post-2nd Vaccine Dose; We Are Not Home and Dry Yet [abstract]. Am J Transplant. 2022; 22 (suppl 3). https://atcmeetingabstracts.com/abstract/transplant-patients-risk-for-sars-cov-2-infection-post-2nd-vaccine-dose-we-are-not-home-and-dry-yet/. Accessed May 18, 2025.« Back to 2022 American Transplant Congress