Effect of Sars-CoV-2 Delta Variant on Post-Vaccination COVID-19 Infection in Solid Organ Transplant Recipients
1Pulmonary and Critical Care Department, Baylor University Medical Center, Dallas, TX, 2Department of Internal Medicine, Baylor University Medical Center, Dallas, TX, 3Center for Advanced Heart and Lung Disease, Baylor University Medical Center, Dallas, TX, 4Department of Pharmacy, Baylor University Medical Center, Dallas, TX
Meeting: 2022 American Transplant Congress
Abstract number: 1632
Keywords: 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: In July 2021, the SARS-CoV-2 Delta variant emerged as the dominant strain in the North Texas area. We reviewed COVID-19 infections post-vaccination in Solid Organ Transplant Recipients (SOTRs) before and after the Delta variant became the dominant strain.
*Methods: This was a retrospective review of SOTRs in the Baylor Scott and White Simmons Transplant Institute who received > 1 dose of COVID-19 vaccine between 01/01/21 to 11/04/21. Those with infections documented after 7/4/21 were included in the post-Delta (Post) group and those prior in the pre-Delta (Pre) group. Demographics, transplant, vaccine, and COVID-19 infection details were recorded. Student’s t-tests, tests of proportions, and ANOVA were used to compare groups.
*Results: Of the 11,328 SOTRs followed actively at the institute, 1,158 (19%) had documented vaccination before 7/4/21; 2,584 (22.8%) had documented vaccination by 11/4/2021. A total of 48 patients (1.8% of vaccinated) had documented COVID-19 infections post-vaccination. Of these, 7 (0.6%) were included in the Pre group and 41 (1.6%) in Post group. The majority in both groups received the Pfizer vaccine (57% vs. 70.7%). The mean age, gender distribution and immunosuppression at presentation were similar between groups (Table). Those in the Post group were diagnosed significantly longer after their last dose of the vaccine (38.3 vs 140.7 days, p=0.00002). Rate of mortality (0% vs 7.3%, p=0.46), need for hospitalization (42% vs 53.7%, p=0.60), and hypoxemia (14% vs 34.1%, p=0.29) were lower in the Pre group, though these were not statistically significant.
*Conclusions: Despite the attenuated immunologic response to vaccination in SOTRs reported by other groups, the overall post-vaccination rate of infection in our transplant institute was low and remained low even in the post-Delta period. There was a higher rate of COVID-19 infection and a trend to more severe COVID-19 outcomes in the Post group. This may be due to waning immunity given the longer time from last vaccine dose or due to variant differences. Future directions include long-term effects of vaccination on COVID-19 risk and optimal vaccination schedules for SOTRs.
To cite this abstract in AMA style:
Tuttle E, Moon J, Grazia TJ, Sam T, Mathai S. Effect of Sars-CoV-2 Delta Variant on Post-Vaccination COVID-19 Infection in Solid Organ Transplant Recipients [abstract]. Am J Transplant. 2022; 22 (suppl 3). https://atcmeetingabstracts.com/abstract/effect-of-sars-cov-2-delta-variant-on-post-vaccination-covid-19-infection-in-solid-organ-transplant-recipients/. Accessed May 18, 2025.« Back to 2022 American Transplant Congress