key: cord-0696677-eaja2u0v
authors: Aslam, Saima; Adler, Eric; Mekeel, Kristin; Little, Susan J.
title: Clinical effectiveness of COVID‐19 vaccination in solid organ transplant recipients
date: 2021-08-03
journal: Transpl Infect Dis
DOI: 10.1111/tid.13705
sha: 4d907e8627bba0b8f4b0718762928556e6a0f914
doc_id: 696677
cord_uid: eaja2u0v

GOAL: We aimed to assess the incidence rate of coronavirus disease 2019 (COVID‐19) in vaccinated versus unvaccinated solid organ transplant recipients (SOTR) at our center. METHODS: We abstracted the following clinical data from our transplant registry from 1/1/2021 to 6/2/2021: demographics, details of COVID‐19 vaccination, incidence of COVID‐19, and related mortality. We calculated incidence of symptomatic COVID‐19 per 1000/person days at risk and incidence rate ratio (IRR). RESULTS: Among 2151 SOTRs, 912 were fully vaccinated, and 1239 were controls (1151 unvaccinated, 88 partially vaccinated). Almost 70% of vaccinated subjects received the mRNA‐1273 vaccine. There were 65 cases of COVID‐19 that occurred during the study period – four occurred among fully vaccinated individuals and 61 among controls (including two in partially vaccinated individuals). Incidence rate for COVID‐19 was 0.065 (95% CI 0.024–0.17) per 1000 person days in vaccinated versus 0.34 (95% CI 0.26–0.44) per 1000/person days in the control group; IRR was 0.19 (95% CI 0.049 −0.503, p < 0.005). There were no COVID‐19 related deaths in the four breakthrough infections and two of 61 (3.3%) among controls. CONCLUSION: We demonstrate real world clinical effectiveness of COVID‐19 vaccination in SOTRs with an almost 80% reduction in the incidence of symptomatic COVID‐19 versus unvaccinated SOTRs during the same time.

prior to 1/1/2021. We calculated incidence of symptomatic COVID-19

per 1000/person days at risk and incidence rate ratio (IRR). We also assessed for difference in cumulative probability of symptomatic COVID-19 in the two groups via Kaplan-Meir curves and associated log-rank test. Sensitivity analysis was done by excluding patients with partial vaccination. We used Stata version 17 (Statacorp, TX, USA) for statistical analysis.

Among 2151 SOTRs, 912 were fully vaccinated, and 1239 were controls (1151 unvaccinated, 88 partially vaccinated) as noted in Table S1 . 

We There are several limitations of this study including the retrospective data collection and single center cohort. Additionally, there is a potential for under-reporting of vaccination status. In general, our patients were either vaccinated at UCSD or at local medical facilities (we share our medical record system with some of these). For others, patients either called us with a vaccination update or we specifically asked and updated this information during clinic visits. There is still a chance of under-reporting this variable but we think that that number is probably low. If there is under-reporting and in fact some vaccinated patients are in the control arm, this would make the IRR more in favor of vaccination and further widen the difference between the two groups.

There is also a potential that we missed some cases of symptomatic COVID-19 but in general we are a regional referral center, and our transplant patients admitted at other centers are generally transferred to us. As noted earlier, some of the local medical centers share medical records with UCSD. Additionally, patients generally call the transplant team with changes in clinical status so that we can assess them further, and thus we are aware of outcomes. We also lacked baseline SARS-CoV-2 serology in our patients as checking serology is not recommended by the FDA at this time and was not routinely performed.

In summary, we demonstrate significant clinical effectiveness of COVID-19 vaccination in SOTRs.

Antibody response to 2-Dose SARS-CoV-2 mRNA Vaccine series in solid organ transplant recipients

Immunogenicity of BNT162b2 mRNA COVID19 vaccine and SARS-CoV-2 infection in lung transplant recipients

Effectiveness of SARS-CoV-2 vaccination in fully vaccinated solid organ transplant recipients

Three doses of an mRNA covid-19 vaccine in solid-organ transplant recipients

Prevalence and predictors of SARS-CoV-2 antibodies among solid organ transplant recipients with confirmed infection

We would like to thank Maaria Malik and Deepa Kurup for their help in data collection and Rongbing Xie for overview of biostatistics.