High acceptance rate of COVID-19 vaccination in liver transplant recipients

Clinical application of COVID-19 vaccine in liver transplant recipients

BACKGROUND

Solid organ transplant (SOT) activities, such as liver transplant, have been greatly influenced by the pandemic of coronavirus disease 2019 (COVID-19), a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Immunosuppressed individuals of liver transplant recipients (LTRs) tend to have a high risk of COVID-19 infection and related complications. Therefore, COVID-19 vaccination has been recommended to be administered as early as possible in LTRs.

DATA SOURCES

The keywords "liver transplant", "SARS-CoV-2", and "vaccine" were used to retrieve articles published in PubMed.

RESULTS

The antibody response following the 1st and 2nd doses of vaccination was disappointingly low, and the immune responses among LTRs remarkably improved after the 3rd or 4th dose of vaccination. Although the 3rd or 4th dose of COVID-19 vaccine increased the antibody titer, a proportion of patients remained unresponsive. Furthermore, recent studies showed that SARS-CoV-2 vaccine could trigger adverse events in LTRs, including allograft rejection and liver injury.

CONCLUSIONS

This review provides the recently reported data on the antibody response of LTRs following various doses of vaccine, risk factors for poor serological response and adverse events after vaccination.

The impact of COVID-19 on liver transplantation: challenges and perspectives

The coronavirus disease 2019 (COVID-19) pandemic presented unique challenges to patients with decompensated cirrhosis awaiting transplant, with respect to accessing medical facilities for routine clinic visits, imaging, laboratory workup, or endoscopies. There was a delay in organ procurement that led to a decrease in the number of liver transplants (LTs) and an increase in the morality of waitlisted patients at the beginning of the pandemic. LT numbers later equalized to pre-pandemic numbers due to combined efforts and adaptability of transplant centers as well as dynamic guidelines. Due to being immunosuppressed, the demographics of LT patients were at an increased risk of infection. Although there is a higher rate of mortality and morbidity in patients with chronic liver disease, LT itself is not a risk factor for mortality in COVID-19. There was no difference in overall mortality in LT patients compared to non-LT patients, and mortality risk factors were the same: age, hypertension, diabetes, obesity, and chronic kidney disease. The most common causes of death were respiratory complications. Liver-related deaths were reported in 1.6% of patients. The optimal timing of liver transplantation post-infection depends on various factors, such as the severity of liver injury, the presence of comorbidities, and the progression of the underlying liver disease. There is not enough data available on COVID-19 cholangiopathy and the number of cases that will be seen in the future that will require LT. There are some concerns of lower immunogenicity of COVID-19 vaccines in LT patients but available evidence suggests that the vaccines are safe and well-tolerated.

New-onset and relapsed liver diseases following COVID-19 vaccination: a systematic review

BACKGROUND

Liver diseases post-COVID-19 vaccination is extremely rare but can occur. A growing body of evidence has indicated that portal vein thrombosis, autoimmune hepatitis, raised liver enzymes and liver injuries, etc., may be potential consequence of COVID-19 vaccines.

OBJECTIVES

To describe the results of a systematic review for new-onset and relapsed liver disease following COVID-19 vaccination.

METHODS

For this systematic review, we searched Proquest, Medline, Embase, PubMed, CINAHL, Wiley online library, Scopus and Nature through the Preferred Reporting Items for Systematic Reviews and Meta Analyses PRISMA guideline for studies on the incidence of new onset or relapsed liver diseases post-COVID-19 vaccination, published from December 1, 2020 to July 31, 2022, with English language restriction.

RESULTS

Two hundred seventy-five cases from one hundred and eighteen articles were included in the qualitative synthesis of this systematic review. Autoimmune hepatitis (138 cases) was the most frequent pathology observed post-COVID-19 vaccination, followed by portal vein thrombosis (52 cases), raised liver enzymes (26 cases) and liver injury (21 cases). Other cases include splanchnic vein thrombosis, acute cellular rejection of the liver, jaundice, hepatomegaly, acute hepatic failure and hepatic porphyria. Mortality was reported in any of the included cases for acute hepatic failure (n = 4, 50%), portal vein thrombosis (n = 25, 48.1%), splanchnic vein thrombosis (n = 6, 42.8%), jaundice (n = 1, 12.5%), raised liver enzymes (n = 2, 7.7%), and autoimmune hepatitis (n = 3, 2.2%). Most patients were easily treated without any serious complications, recovered and did not require long-term hepatic therapy.

CONCLUSION

Reported evidence of liver diseases post-COIVD-19 vaccination should not discourage vaccination against this worldwide pandemic. The number of reported cases is relatively very small in relation to the hundreds of millions of vaccinations that have occurred and the protective benefits offered by COVID-19 vaccination far outweigh the risks.

Solid Organ Rejection following SARS-CoV-2 Vaccination or COVID-19 Infection: A Systematic Review and Meta-Analysis

Background: Solid organ rejection post-SARS-CoV-2 vaccination or COVID-19 infection is extremely rare but can occur. T-cell recognition of antigen is the primary and central event that leads to the cascade of events that result in rejection of a transplanted organ. Objectives: To describe the results of a systematic review for solid organ rejections following SARS-CoV-2 vaccination or COVID-19 infection. Methods: For this systematic review and meta-analysis, we searched Proquest, Medline, Embase, Pubmed, CINAHL, Wiley online library, Scopus and Nature through the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines for studies on the incidence of solid organ rejection post-SARS-CoV-2 vaccination or COVID-19 infection, published from 1 December 2019 to 31 May 2022, with English language restriction. Results: One hundred thirty-six cases from fifty-two articles were included in the qualitative synthesis of this systematic review (56 solid organs rejected post-SARS-CoV-2 vaccination and 40 solid organs rejected following COVID-19 infection). Cornea rejection (44 cases) was the most frequent organ observed post-SARS-CoV-2 vaccination and following COVID-19 infection, followed by kidney rejection (36 cases), liver rejection (12 cases), lung rejection (2 cases), heart rejection (1 case) and pancreas rejection (1 case). The median or mean patient age ranged from 23 to 94 years across the studies. The majority of the patients were male (n = 51, 53.1%) and were of White (Caucasian) (n = 51, 53.7%) and Hispanic (n = 15, 15.8%) ethnicity. A total of fifty-six solid organ rejections were reported post-SARS-CoV-2 vaccination [Pfizer-BioNTech (n = 31), Moderna (n = 14), Oxford Uni-AstraZeneca (n = 10) and Sinovac-CoronaVac (n = 1)]. The median time from SARS-CoV-2 vaccination to organ rejection was 13.5 h (IQR, 3.2–17.2), while the median time from COVID-19 infection to organ rejection was 14 h (IQR, 5–21). Most patients were easily treated without any serious complications, recovered and did not require long-term allograft rejection therapy [graft success (n = 70, 85.4%), graft failure (n = 12, 14.6%), survived (n = 90, 95.7%) and died (n = 4, 4.3%)]. Conclusion: The reported evidence of solid organ rejections post-SARS-CoV-2 vaccination or COIVD-19 infection should not discourage vaccination against this worldwide pandemic. The number of reported cases is relatively small in relation to the hundreds of millions of vaccinations that have occurred, and the protective benefits offered by SARS-CoV-2 vaccination far outweigh the risks.

Mycophenolate mofetil decreases humoral responses to three doses of SARS-CoV-2 vaccine in liver transplant recipients

BACKGROUND AND AIMS

After 2 doses, the efficacy of anti-SARS-CoV-2 vaccination seems to be lower in solid organ transplant recipients than in the immunocompetent population. The objective of this study was to determine the humoral response rate after vaccination, including with a booster dose, and to identify risk factors for non-responsiveness in liver transplant recipients.

METHODS

We included all patients seen in consultation in two French liver transplant centres between January 1, 2021, and March 15, 2021.

RESULTS

598 liver transplant recipients were enrolled and 327 were included for analysis. Sixteen patients received one dose, 63 patients two doses and 248 patients three doses. Anti-SARS-Cov-2 antibodies were detected in 242 out of 327 (74.0%) liver transplant patients after vaccination. Considering an optimal serologic response defined as an antibody titre >260 BAU/ml, 172 patients (52.6%) were responders. Mycophenolate mofetil (MMF) treatment was an independent risk factor for a failure to develop anti-SARS-CoV-2 antibodies after vaccination (OR 0.458; 95%CI 0.258-0.813; p = .008). Conversely, male gender (OR 2.247, 95%CI 1.194-4.227; p = .012) and receiving an mRNA vaccine (vs a non-mRNA vaccine) (OR 4.107, 95%CI 1.145-14.731; p = .030) were independent predictive factors for developing an optimal humoral response after vaccination. None of the patients who received the vaccine experienced any serious adverse events.

CONCLUSIONS

Even after a third booster dose, response rate to vaccination is decreased in liver transplant recipients. MMF appears to be a major determinant of seroconversion and optimal response to vaccination in these patients.

COVID-19 Vaccine Acceptance among Liver Transplant Recipients

(1) Background: COVID-19 vaccination hesitancy is a threat for fragile patients. We aimed to evaluate COVID-19 vaccination hesitancy and its reasons in a population of liver transplant (LT) recipients. (2) Methods: In February 2021, a questionnaire on COVID-19 vaccines was sent to LT patients followed at our liver transplant outpatient clinic in Milan, Italy. Sociodemographic and clinical characteristics were recorded. Patients were defined as willing, hesitant, or refusing and their reasons were investigated. Associations between baseline characteristics and willingness were evaluated. Since March 2021, when the COVID-19 vaccines became available for LT candidates and recipients in Italy, the entire cohort of LT recipients was contacted by phone and called for vaccination, and the rate of refusals recorded. (3) Results: The web-based survey was sent to 583 patients, of whom 190 responded (response rate of 32.6%). Among the respondents to the specific question about hesitancy (184), 157 (85.3%) were willing to be vaccinated against COVID-19, while 27 (14.7%) were hesitant. Among the hesitant, three were totally refusing, for a refusal rate of 1.6%. Thirteen hesitant patients (48.1%) answered that their COVID-19 vaccination hesitancy was influenced by being a transplant recipient. The fear of adverse effects was the main reason for refusal (81.5%). Of the 711 LT patients followed at our center, 668 got fully vaccinated, while 43 (6.1%) of them refused the scheduled vaccination. (4) Conclusions: Most patients accepted COVID-19 vaccines, although 6.1% refused the vaccine. Since it is crucial to achieve adequate vaccination of LT patients, it is very important to identify the reasons influencing COVID-19 vaccination hesitancy so that appropriate and targeted communication strategies can be established and specific vaccination campaigns further implemented.