Project description:GoalWe aimed to assess the incidence rate of coronavirus disease 2019 (COVID-19) in vaccinated versus unvaccinated solid organ transplant recipients (SOTR) at our center.MethodsWe 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).ResultsAmong 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.ConclusionWe 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.
Project description:In response to the COVID-19 pandemic, SARS-CoV-2 vaccines have been developed at an unparalleled speed, with 14 SARS-CoV-2 vaccines currently authorized. Solid-organ transplant (SOT) recipients are at risk for developing a higher rate of COVID-19-related complications and therefore they are at priority for immunization against SARS-CoV-2. Preliminary data suggest that although SARS-CoV-2 vaccines are safe in SOT recipients (with similar rate of adverse events than in the general population), the antibody responses are decreased in this population. Risk factors for poor vaccine immunogenicity include older age, shorter time from transplantation, use of mycophenolate and belatacept, and worse allograft function. SOT recipients should continue to be advised to maintain hand hygiene, use of facemasks, and social distancing after SARS-CoV-2 vaccine. Vaccination of household contacts should be also prioritized. Although highly encouraged for research purposes, systematic assessment in clinical practice of humoral and cellular immune responses after SARS-CoV-2 vaccination is controversial, since correlation between immunological findings and clinical protection from severe COVID-19, and cutoffs for protection are currently unknown in SOT recipients. Alternative immunization schemes, including a booster dose, higher doses, and modulation of immunosuppression during vaccination, need to be assessed in the context of well-designed clinical trials.
Project description:BackgroundWe studied the safety and reactogenicity SARS-CoV-2 mRNA vaccines in transplant recipients because immunosuppressed patients were excluded from vaccine trials.MethodsUS transplant recipients were recruited into this prospective cohort study through social media; those who completed the full vaccine series between December 9, 2020 and March 1, 2021 were included. We collected demographics, medical history, and safety information within 7 d after doses 1 and 2 (D1, D2). Associations between characteristics and reactions were evaluated using modified Poisson regression.ResultsWe studied 741 transplant recipients who underwent BNT162b2 (54%) or mRNA-1273 (46%) vaccination. Median (interquartile range) age was 60 (44-69) y, 57% were female, and 10% were non-White. Although local site reactions decreased after D2 (85% D1 versus 78% D2, P < 0.001), systemic reactions increased (49% D1 versus 69% D2, P < 0.001). Younger participants were more likely to develop systemic symptoms after D1 (adjusted incidence rate ratio [aIRR] per 10 y = 0.850.900.94, P < 0.001) and D2 (aIRR per 10 y = 0.910.930.96, P < 0.001). Participants who experienced pain (aIRR = 1.111.662.47, P = 0.01) or redness (aIRR = 1.833.928.41, P < 0.01) were more likely to develop an antibody response to D1 of mRNA vaccines. No anaphylaxis, neurologic diagnoses, or SARS-CoV-2 diagnoses were reported. Infections were minimal (3% after D1, <0.01% after D2). One patient reported incident acute rejection post-D2.ConclusionsIn solid organ transplant recipients undergoing mRNA vaccination, reactogenicity was similar to that reported in the original trials. Severe reactions were rare. These early safety data may help address vaccine hesitancy in transplant recipients.
Project description:ObjectivesThe SARS-CoV-2 pandemic poses a great threat to global health, particularly in solid organ transplant recipients (SOTRs). A 3-dose mRNA vaccination protocol has been implemented for the majority of SOTRs, yet their immune responses are less effective compared to healthy controls (HCs).MethodsWe analyzed the humoral immune responses against the vaccine strain and variants of concern (VOC), including the highly mutated-omicron variant in 113 SOTRs, of whom 44 had recovered from COVID-19 (recovered-SOTRs) and 69 had not contracted the virus (COVID-naïve). In addition, 30 HCs, 8 of whom had recovered from COVID-19, were also studied.ResultsHere, we report that three doses of the mRNA vaccine had only a modest effect in eliciting anti-viral antibodies against all viral strains in the fully vaccinated COVID-naive SOTRs (n = 47). Only 34.0% of this group of patients demonstrated both detectable anti-RBD IgG with neutralization activities against alpha, beta, and delta variants, and only 8.5% of them showed additional omicron neutralizing capacities. In contrast, 79.5% of the recovered-SOTRs who received two doses of vaccine demonstrated both higher anti-RBD IgG levels and neutralizing activities against all VOC, including omicron.ConclusionThese findings illustrate a significant impact of previous infection on the development of anti-SARS-CoV-2 immune responses in vaccinated SOTRs and highlight the need for alternative strategies to protect a subset of a lesser-vaccine responsive population.
Project description:Detection of SARS-CoV-2 viral RNA by RT-PCR assays is the primary diagnostic test for COVID-19. Cycle threshold (CT ) values generated by some of these assays provide inversely proportional proxy measurements of viral load. The clinical implications of CT values are incompletely characterized, particularly in solid organ transplant (SOT) recipients. We conducted a retrospective chart review of 25 adult SOT recipients admitted to the Yale New Haven Health System between March 1 and May 15, 2020, analyzing 50 test results to investigate the clinical implications of SARS-CoV-2 CT values in this population. Initial CT values from upper respiratory tract samples were significantly higher in patients on tacrolimus, but were not associated with admission severity nor highest clinical acuity. Viral RNA was detected up to 38 days from symptom onset with a gradual increase in CT values over time. In five patients with serial testing, CT values <35.0 were detected >21 days after symptom onset in 4/5 and ≥27 days in 2/5, demonstrating prolonged RNA detection. These data describe SARS-CoV-2 viral dynamics in SOT patients and suggest that CT values may not be useful to predict COVID-19 severity in SOT patients. SARS-CoV-2 CT values may be more useful in informing infection prevention measures.
Project description:BackgroundThis is a descriptive study to characterize rates of SARS-CoV-2 infection in pediatric solid organ transplant (SOT) recipients during the early days of the pandemic. We hypothesized that asymptomatic infection may represent a large proportion of SARS-CoV-2 infection in ped SOT recipients.MethodsWe queried OTTR for all pediatric SOT recipients followed at our center and reviewed medical records to identify patients tested for SARS-CoV-2 between March 15, 2020 through June 30, 2021. Patients were tested by PCR: prior to planned procedures or because of symptoms; OR: tested by measurement of IgG to spike protein with their routine labs q 2-monthly. A positive PCR was called acute infection. A positive IgG with negative PCR was called convalescence. For immunologic studies, blood was obtained when the PCR or IgG was positive. Statistical comparisons were made between (i) acute infection vs. convalescence; (ii) acute infection vs. SOT recipients without infection (called healthy controls); (iii) LT vs. SB/MVT; (iii) positive vs. negative test result.ResultsOf 257 liver transplant (LT) recipients, 99 were tested: 6 were PCR positive,13 were antibody positive. Of 150 small bowel (SB)/ multi-visceral transplant (MVT) recipients, 55 were tested: 4 were PCR positive, 6 were antibody positive. Of 8 simultaneous liver, kidney transplant recipients, 3 were tested: 1 was PCR positive. Symptoms when present were mostly mild. Patients with a positive test result were younger (6.3 vs. 10.0-years; p=0.017). We observed a rapid decline in viral load within 96-hours without a change in immunosuppression. Antibody lasted >8-months beyond the time it was monitored. Acute infection was associated with increased CD4 and CD8 TEM cell frequency (p=0.04, p=0.03 respectively), decreased IFN-γ production from T-cells (2.8% vs.11.3% p=0.006), and decreased CD8 TEMRA frequency (4.56% vs.11.70% p=0.006).ConclusionEarly in the pandemic, COVID-19 disease was mostly mild in pediatric SOT recipients with no rejection, patient death, or graft loss observed.
Project description:ObjectivesThe study aim was to assess predictors of negative antibody response (AbR) in solid organ transplant (SOT) recipients after the first booster of SARS-CoV-2 vaccination.MethodsSolid organ transplant recipients receiving SARS-CoV-2 vaccination were prospectively enrolled (March 2021-January 2022) at six hospitals in Italy and Spain. AbR was assessed at first dose (t0), second dose (t1), 3 ± 1 month (t2), and 1 month after third dose (t3). Negative AbR at t3 was defined as an anti-receptor binding domain titre <45 BAU/mL. Machine learning models were developed to predict the individual risk of negative (vs. positive) AbR using age, type of transplant, time between transplant and vaccination, immunosuppressive drugs, type of vaccine, and graft function as covariates, subsequently assessed using a validation cohort.ResultsOverall, 1615 SOT recipients (1072 [66.3%] males; mean age±standard deviation [SD], 57.85 ± 13.77) were enrolled, and 1211 received three vaccination doses. Negative AbR rate decreased from 93.66% (886/946) to 21.90% (202/923) from t0 to t3. Univariate analysis showed that older patients (mean age, 60.21 ± 11.51 vs. 58.11 ± 13.08), anti-metabolites (57.9% vs. 35.1%), steroids (52.9% vs. 38.5%), recent transplantation (<3 years) (17.8% vs. 2.3%), and kidney, heart, or lung compared with liver transplantation (25%, 31.8%, 30.4% vs. 5.5%) had a higher likelihood of negative AbR. Machine learning (ML) algorithms showing best prediction performance were logistic regression (precision-recall curve-PRAUC mean 0.37 [95%CI 0.36-0.39]) and k-Nearest Neighbours (PRAUC 0.36 [0.35-0.37]).DiscussionAlmost a quarter of SOT recipients showed negative AbR after first booster dosage. Unfortunately, clinical information cannot efficiently predict negative AbR even with ML algorithms.