Poor immune response to coronavirus disease vaccines in decompensated cirrhosis patients and liver transplant recipients

Distinct immune memory induced by SARS-CoV-2 in convalescent liver transplant recipients

The understanding of how the host immune response differs in T-cell phenotype and memory formation during SARS-CoV-2 infection in liver transplant recipients (LTRs) remains limited. LTRs who recovered from COVID-19 infection without prior vaccination represent a unique population for studying immune responses to SARS-CoV-2. Six LTRs with positive neutralizing antibodies (nAb+) and six LTRs with negative nAb (nAb-) were included at 6 months following COVID-19 infection. It was found that nAb+ LTRs had higher anti-RBD IgG titers and greater neutralizing percent inhibition compared to nAb- LTRs. Fifteen T-cell subsets were identified in COVID-19 convalescent LTRs, and it was shown that only terminal effector CD8+ - 3 decreased in the nAb+ group, while elevated IL-10 expression levels were found in the nAb- group. After stimulation with the SARS-CoV-2 XBB spike peptide pool in vitro, it was observed that the nAb+ group exhibited an increase in effector memory CD4+ cells with lower PD-1 expression, a reduction in effector memory CD4+ - 2 cells, and terminal effector CD8+ - 3 cells, while the nAb- group showed high expression of CTLA-4 and IL-10 in terminal effector CD8+ - 3 cells. Four SARS-CoV-2-specific T-cell subsets were identified, with high expression of TNF-α and IFN-γ in terminal effector CD8+ - 1 and terminal effector CD8+ - 2 cells in both groups. Perforin was mainly detected in terminal effector CD8+ - 2 cells in nAb+ LTRs. In addition to these proportional differences, stem cell memory CD4+ cells with higher IL-17A expression and stem cell memory CD8+ cells with higher CTLA-4 expression were also found in nAb- LTRs. These findings suggest that LTRs who developed nAb+ following SARS-CoV-2 infection exhibit stronger T-cell responses, with more robust immune activation and memory recall, compared to nAb- LTRs. This study underscores the importance of understanding T-cell responses during SARS-CoV-2 recovery for guiding vaccination strategies and managing immunity in LTRs.

Immunogenicity of COVID-19 vaccines in patients with cirrhosis: A meta-analysis

The immunogenicity of COVID-19 vaccines in patients with liver cirrhosis remains largely unknown. The purpose of this meta-analysis was to investigate the immunogenicity of COVID-19 vaccines in patients with cirrhosis and compare the humoral and cellular immune responses following complete COVID-19 vaccination between cirrhosis patients and healthy controls. A systematic literature search was conducted in PubMed, EMBASE, and Web of Science from 1 January 2020 to 22 August 2023. Sixteen studies with 2127 cirrhosis patients were included. The pooled seroconversion rate in patients with cirrhosis following complete COVID-19 vaccination was 92.4% (95% CI, 86.2%-96%, I2 = 90%) with significant between-study heterogeneity. Moreover, COVID-19 vaccination elicited a higher humoral immune response in patients of compensated cirrhosis as compared with decompensated cirrhosis (RR = 1.069, 95% CI, 1.011-1.131, I2 = 17%, p = .019). Additionally, 10 studies were included for comparison analysis of seroconversion rate between cirrhosis patients and healthy controls. The results showed that the seroconversion rate in patients with cirrhosis was slightly lower compared with healthy controls (RR = 0.972, 95% CI, 0.955-0.989, I2 = 66%, p = .001). Meanwhile, the pooled RR of cellular immune response rate for cirrhosis patients vs. healthy controls was 0.678 (95% CI, 0.563-0.817, I2 = 0, p < .0001). Our meta-analysis demonstrated that COVID-19 vaccination elicited diminished humoral and cellular immune responses in patients of cirrhosis. Patients with cirrhosis particularly decompensated cirrhosis who have completed full-doses of COVID-19 vaccination should receive continuous attention and preemptive measures.

Safety and Efficacy of SARS-CoV-2 Vaccines in Patients With Chronic Liver Diseases: A Systematic Review and Meta-Analysis

Objectives

This review aimed to assess the safety and efficacy of SARS-CoV-2 vaccines in patients with chronic liver disease (CLD).

Methods

Cochrane Central Register of Controlled Trials, PubMed, Embase, and Web of Science were searched from 2020 to 2024. Data was extracted following Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. The random-effects model (when I2 ≥ 50%) or fixed effect model (I2 < 50%) was used.

Results

29 studies were included in this review. Compared to healthy controls (HCs), patients with CLD had a higher incidence of mild adverse events (RR = 1.60, p < 0.001), while the incidence of severe adverse events was similar (RR = 1.08, p = 0.92). Seropositivity rates of three antibodies in patients were lower than in HCs [neutralizing antibody (RR = 0.86, p = 0.002), anti-spike antibody (RR = 0.97, p = 0.06) and anti-receptor binding domain antibody (RR = 0.95, p = 0.04)]. Compared to unvaccinated patients, vaccinated patients had lower rates of SARS-CoV-2 infection, hospitalization and death (p ≤ 0.05).

Conclusion

SARS-CoV-2 vaccines showed good safety and efficacy in CLD patients, but antibody response appeared to be decreased. Therefore, SARS-CoV-2 vaccines and booster doses should be given priority in this vulnerable population.

COVID-19 Vaccination in Liver Cirrhosis: Safety and Immune and Clinical Responses

Introduction

Three years after the beginning of the SARS-CoV-2 pandemic, the safety and efficacy of COVID-19 vaccination in liver cirrhosis (LC) patients remain controversial. We aimed to study the safety, immunological, and clinical responses of LC patients to COVID-19 vaccination.

Methods

Prospective multicentric study in adults with LC eligible for COVID-19 vaccination, without prior known infection. Patients were followed up until the timing of a booster dose, SARS-CoV-2 infection, or death. Spike-protein immunoglobulin G antibody titers for SARS-CoV-2 at 2 weeks, 3 months, and 6 months postvaccination were assessed. Antibody titers <33.8 binding antibody units (BAU)/mL were considered seronegative and <200 BAU/mL suboptimal. Postvaccination infection and its severity were registered.

Results

We included 124 LC patients, 81% males, mean aged 61 ± 10 years, with a mean follow-up of 221 ± 26 days. Alcohol was the most common (61%) cause of cirrhosis, and 7% were under immunosuppressants for autoimmune hepatitis; 69% had portal hypertension, 42% had a previous decompensation, and 21% had a Child-Pugh-Turcotte score of B/C. The type of vaccine administrated was BNT162b2 (n = 59, 48%), ChAdOx1nCoV-19 (n = 45, 36%), mRNA-1273 (n = 14, 11%), and Ad26.COV2.S (n = 6, 5%). Eighteen percent of the patients reported adverse events after vaccination, none serious. Median [Q1; Q3] antibody titers were 1,185 [280; 2,080] BAU/mL at 2 weeks, 301 [72; 1,175] BAU/mL at 3 months, and 192 [49; 656] BAU/mL at 6 months. There were seronegative and suboptimal antibody responses in 8% and 23% of the patients at 2 weeks, 16% and 38% at 3 months, and 22% and 48% at 6 months. Older age and adenovirus vector vaccines were the only factors associated with seronegative and suboptimal responses at 2 weeks and 3 months (p < 0.05) in a multivariable logistic regression analysis. Eleven patients (9%) were infected with SARS-CoV-2 during follow-up (3.8-6.6 months postvaccination), all with mild disease. There were no differences regarding the type of vaccine, and 73% had antibody titers >200 BAU/mL at 3 months.

Conclusion

COVID-19 vaccines in patients with LC were safe, without serious adverse events. The humoral and clinical responses were similar to the reported for the general population. Humoral response was adversely impacted by older age and adenovirus vector vaccines and unrelated to the liver disease severity.

Measures to Increase Immunogenicity of SARS-CoV-2 Vaccines in Solid Organ Transplant Recipients: A Narrative Review

Purpose of review: To review the data on the immunogenicity of COVID-19 vaccines, administered by different strategies, in solid organ transplant recipients (SOTRs). Recent findings: COVID-19 booster vaccines were given to SOTRs as a widespread practice in many transplant centers, mostly as the third and/or fourth dose in an extended vaccine series, with a significantly improved humoral response compared with the initial two-dose scheme. However, one-third of SOTRs remained unresponsive, despite these boosters. Next steps: Vaccination with standard dosing remains the most feasible strategy for attaining protection against COVID-19. Additional booster doses and temporarily holding or reducing mycophenolate mofetil/mycophenolic acid may provide immunogenicity to vaccines, according to recent studies demonstrating some efficacy with these measures. Preexposure prophylaxis with monoclonal antibodies showed benefit in immunocompromised patients but is no longer recommended by the National Institutes of Health (NIH) due to diminished efficacy against Omicron and recent variants. Screening for the presence and titers of SARS-CoV-2-specific antibodies in SOTRs is not recommended in most clinical settings. T cell-based techniques are needed to evaluate vaccine efficacy and risk of infection. As SARS-CoV-2 continues to evolve, new vaccines based on conservative protein component/complexes of the COVID virus, in addition to its spike protein, are warranted to offer prolonged protection.

Heterologous COVID-19 Vaccination and Booster with mRNA Vaccine Provide Enhanced Immune Response in Patients with Cirrhosis: A Prospective Observational Study

This study aimed to evaluate the antibody and cellular responses to different coronavirus 2019 (COVID-19) vaccination regimens in patients with cirrhosis and to assess the antibody response after a vaccine booster. We conducted a prospective observational study of 89 patients with cirrhosis and 41 healthy volunteers who received two COVID-19 vaccine doses. Next, we prospectively evaluated 24 patients with cirrhosis who received a booster COVID-19 vaccine dose. In both studies, blood samples were collected before and 4 weeks after vaccination, and anti-spike receptor-binding domain protein IgG levels, T-cell phenotypes, and effector functions were assessed. The heterologous vaccine regimen (CoronaVac [SV]/AstraZeneca [AZ]) produced a better antibody response and CD4+IFNg+ T cell response compared to homogeneous vaccine regimens. The antibody response after the second dose of the vaccine was similar in patients with cirrhosis and healthy volunteers. Patients who received a booster dose of the mRNA vaccine had significantly increased antibody titers compared to those who received the AZ vaccine. In patients with cirrhosis, heterologous vaccination with SV/AZ resulted in a better immune response than the AZ/AZ and SV/SV regimens. Moreover, a booster dose of the mRNA vaccine led to a greater increase in antibody titers compared to the AZ vaccine.

SARS-CoV-2 and the liver: clinical and immunological features in chronic liver disease

SARS-CoV-2 infection may affect the liver in healthy individuals but also influences the course of COVID-19 in patients with chronic liver disease (CLD). As described in healthy individuals, a strong SARS-CoV-2-specific adaptive immune response is important for the outcome of COVID-19, however, knowledge on the adaptive immune response in CLD is limited.Here, we review the clinical and immunological features of SARS-CoV-2 infection in individuals with CLD. Acute liver injury occurs in many cases of SARS-CoV-2 infection and may be induced by multiple factors, such as cytokines, direct viral infection or toxic effects of COVID-19 drugs. In individuals with CLD, SARS-CoV-2 infection may have a more severe course and promote decompensation and particularly in patients with cirrhosis. Compared with healthy individuals, the SARS-CoV-2-specific adaptive immune responses is impaired in patients with CLD after both, natural infection and vaccination but improves at least partially after booster vaccination.Following SARS-CoV-2 vaccination, rare cases of acute vaccine-induced liver injury and the development of autoimmune-like hepatitis have been reported. However, the concomitant elevation of liver enzymes is reversible under steroid treatment.

Liver Transplantation: Protocol for Recipient Selection, Evaluation, and Assessment

Liver transplantation (LT) is the definitive therapy for patients with end-stage liver disease, acute liver failure, acute-on-chronic liver failure, hepatocellular carcinoma, and metabolic liver diseases. The acceptance of LT in Asia has been gradually increasing and so is the expertise to perform LT. Preparing a patient with cirrhosis for LT is the most important aspect of a successful LT. The preparation for LT begins with the first index decompensation for a patient with cirrhosis. Patients planned for LT should undergo a thorough screening for infections, and a complete cardiac, pulmonology, and psychosocial evaluation pre-LT. In this review, we discuss the indications and contraindications of LT and the evaluation and assessment of patients with liver disease planned for LT.

Efficacy, Safety and Immunogenicity of Anti-SARS-CoV-2 Vaccines in Patients with Cirrhosis: A Narrative Review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 2019 (COVID-19), has led to a pandemic with more than 6.5 million deaths worldwide. Patients with liver cirrhosis (PWLC) are regarded as prone to severe COVID-19. Vaccination against SARS-CoV-2 has been proven to be the most effective measure against COVID-19 and a variety of different vaccines have been approved for use; namely mRNA and vector-based, inactivated, whole virion, and protein subunit vaccines. Unfortunately, only a small number of PWLC were included in phase I-III vaccine trials, raising concerns regarding their efficacy and safety in this population. The authors, in this review, present available data regarding safety and efficacy of anti-SARS-CoV-2 vaccination in PWLC and discuss post-vaccination antibody responses. Overall, all vaccines seem to be extremely safe, with only a few and insignificant adverse events, and efficient, leading to lower rates of hospitalization and COVID-19-related mortality. T- and B-cell responses, on the other hand, remain an enigma, especially in patients with decompensated disease, since these patients show lower titers of anti-SARS-CoV-2 antibodies in some studies, with a more rapid waning. However, this finding is not consistent, and its clinical impact is still undetermined.

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.