ABSTRACT
BACKGROUND: Clinical effectiveness of coronavirus disease 2019 (COVID-19) vaccination in solid organ transplant recipients (SOTRs) is not well documented despite multiple studies demonstrating sub-optimal immunogenicity. METHODS: We reviewed medical records of eligible SOTRs at a single center to assess vaccination status and identify cases of symptomatic COVID-19 from January 1 to August 12, 2021. We developed a Cox proportional hazards model using the date of vaccination and time since transplantation as a time-varying covariate with age and gender as potential time-invariant confounders. Survival curves were created using the parameters estimated from the Cox model. RESULTS: Among 1904 SOTRs, 1362 were fully vaccinated (96% received mRNA vaccines) and 542 were either unvaccinated (n = 470) or partially vaccinated (n = 72). There were 115 cases of COVID-19, of which 12 occurred in fully vaccinated individuals. Cox regression with the date of vaccination and time since transplantation as the time-varying co-variates showed that after baseline adjustment for age and sex, being fully vaccinated had a significantly lower hazard for COVID-19, hazard ratio (HR) = 0.29 and 95% confidence interval ([CI] 0.09, 0.91). CONCLUSION: We found that 2-dose mRNA COVID-19 vaccination was protective of symptomatic COVID-19 in vaccinated versus unvaccinated SOTRs. TWEET: COVID-19 vaccination was associated with a significantly lower hazard for symptomatic COVID-19 (HR 0.29; 95% CI 0.09, 0.91) among 1904 SOT recipients at a single center from January 1 to August 12, 2021.