Coronavirus disease 2019 vaccination is protective of clinical disease in solid organ transplant recipients

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.

Serologic response to a third dose of an mRNA-based SARS-CoV-2 vaccine in lung transplant recipients

“…First, we only focused on serologic response to vaccination, whereas protection against severe COVID-19 is a more important outcome measure. SARS-CoV-2 vaccines have been shown to protect solid organ transplant recipients against severe COVID-19 [ 19 ], but it remains to be determined to what degree serologic response correlates with clinical protection in solid organ transplant recipients. Even for the general population, clinically relevant cut-off values for antibody levels that associate with clinical protection are not yet available [ 20 ].…”

SARS‐CoV‐2 vaccine clinical efficacy in SOT: What we know and our current gaps

“…At our institution, two of 12 breakthrough cases required supplemental oxygen, although five of 12 were admitted with one mortality; eight patients received monoclonal antibodies. 25 The Saharia et al's paper is the first multicenter series detailing clinical manifestations of breakthrough COVID-19 in SOTR. However, significant bias exists both in the manner of case solicitation (in favor of hospitalized and more severe cases) and definitions of disease (again favoring more severe disease).…”

“…Among these 43, 25.8% had critical illness, and 15.2% required mechanical ventilation; with associated with 7% mortality. In other series of breakthrough infections, clinical outcomes are variable, with mortality ranging from 0%–22% 15,24,25 . Reported disease severity has been variable as well and may be related to use of monoclonal antibodies at some centers.…”

“… 6 , 8 , 9 Only a few studies have assessed clinical outcomes and demonstrate reduced rate of symptomatic COVID‐19 and reduced mortality. 10 , 11 , 12 In one single center study, there was an almost 80% reduction in risk of symptomatic COVID‐19 compared to unvaccinated SOTR. 12 However, these clinical effectiveness studies were done prior to the onset of the Delta and now Omicron variant‐related surges.…”

“… 10 , 11 , 12 In one single center study, there was an almost 80% reduction in risk of symptomatic COVID‐19 compared to unvaccinated SOTR. 12 However, these clinical effectiveness studies were done prior to the onset of the Delta and now Omicron variant‐related surges.…”