Immunogenicity of COVID-19 vaccines in chronic liver disease patients and liver transplant recipients: A systematic review and meta-analysis

High Rate of Antibody Response to Multiple Doses of the COVID-19 Vaccine in Liver Transplant Recipients: Analysis of Predictive Factors

BACKGROUND

The COVID-19 pandemic highlighted the vulnerability of immunocompromised individuals, including liver transplant recipients (LTRs), who often exhibit reduced vaccine immunogenicity. While initial vaccine doses and subsequent boosters improved immune response, LTRs were prioritized for vaccination. Studies have shown increased antibody response after each booster dose. Vaccine hesitancy, defined as delayed or refused vaccination despite availability, poses a public health challenge, often fueled by misinformation. This study aimed to evaluate anti-spike antibody responses in vaccinated LTRs after two initial doses and at least one booster, also assessing adherence to subsequent doses.

METHODS

We conducted a retrospective observational study at a transplant center in Milan, Italy, between January 2021 and December 2023. LTRs who had received four or more doses of mRNA vaccines (Pfizer or Moderna) were included. Anti-spike antibody levels were measured 60-80 days after each dose. Data on vaccination status were collected in January 2024. Statistical analysis was performed to compare antibody responses and identify predictive factors.

RESULTS

LTRs showed a significant increase in anti-spike antibody responses after the first booster compared to the second dose with a trend versus a further increase following the fourth dose in a subgroup of the patients receiving two booster doses. However, adherence to booster doses decreased over time. In LTRs, predictors of a weaker response after the second dose were chronic kidney disease and metabolic etiology at transplant.

CONCLUSIONS

The study highlighted that in LTRs, multiple doses of the COVID-19 vaccine led to a continuous increase in anti-spike antibody responses. The progressive decline in adherence of LTRs "to further booster doses" should be related to the fact that after the spread of vaccination programs worldwide, COVID-19 is still a current infection, but it is much less severe than before.

Ursodeoxycholic acid relieves clinical severity of COVID-19 in patients with chronic liver diseases

Background

The potential effect of ursodeoxycholic acid (UDCA) on the clinical outcomes of SARS-CoV-2 in patients with chronic liver diseases has been a subject of ongoing debate since the onset of the SARS-CoV-2 pandemic in 2019. This study aims to investigate the effect of UDCA on the prognosis of SARS-CoV-2 infection in patients with chronic liver diseases.

Methods

A total of 926 patients with chronic liver diseases who contracted their first SARS-CoV-2 infection during December 2022 to January 2023, were included in this study. Participants were divided into two groups based on the use of UDCA: the UDCA cohort (n = 329) and the non-UDCA cohort (n = 597). After performing a 1:1 age-and sex-matching, the analysis proceeded with 309 patients from each group for further evaluation.

Results

In the UDCA-treated cohort, the incidence of asymptomatic SARS-CoV-2 infections was significantly higher, with 30.1% of patients affected, compared to 6.47% in the non-UDCA group (p < 0.0001). Multivariable analysis identified UDCA as a protective factor against symptomatic infections, yielding an odds ratio (OR) of 4.77 (95% CI: 2.70-8.44, p < 0.001). Furthermore, age over 50 was found to be a risk factor for asymptomatic infections in the UDCA cohort, with an adjusted OR of 1.51 (95% CI: 1.01-2.24, p = 0.05).

Conclusion

The study suggests that UDCA therapy may improve clinical outcomes in patients with chronic liver diseases patients who are infected with SARS-CoV-2, highlighting its potential role in improving prognosis within this vulnerable population. However, further research is required to validate these findings and to elucidate the mechanisms underlying UDCA's protective effect.

Clinical outcomes of COVID-19 infection in liver transplant recipients based on vaccination status

Background

COVID-19 disease burden has been mitigated by vaccination; however, concerns persist regarding weakened immune responses in liver transplant (LT) recipients. This study investigates COVID-19 outcomes in LT recipients based on vaccination status.

Methods

This single-center retrospective study identified LT recipients with PCR-confirmed COVID-19 infection from 03/01/2020 to 07/31/2023. Logistic regression analyses were conducted, adjusting for age, race, co-morbidities, number of immunosuppressive agents, and infection date.

Results

Of 1,787 registered LT recipients, 361 had confirmed COVID-19 infection. Of those, 136 were unvaccinated and 225 were vaccinated. 13% had 1 vaccine dose, 31% had 2 vaccine doses, and 56% had 3 vaccine doses prior to infection. Logistic regression found higher mortality (p = 0.001) and hospitalization (p = 0.016) rates for older recipients, while those with 3 or more vaccine doses had lower mortality (p = 0.039) and hospitalization (p = 0.008) rates. Chronic kidney disease (CKD) increased risk of hospitalization (p < 0.001). Adjusting for the date when the Omicron variant became locally predominant, the protective effect from 3 or more vaccine doses declined to an OR (95% CI) of 0.58 (0.15-2.23), p = 0.39.

Conclusions

Three or more COVID-19 vaccine doses could decrease mortality for LT recipients, particularly older recipients and those with CKD. These individuals may benefit from vaccination and other interventions.

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.

Serological responses to COVID-19 vaccination in patients with chronic liver diseases

Longitudinal analysis of antibody responses following three-dose COVID-19 vaccination in patients with chronic liver disease (CLD) has been limited. From August 2021 to February 2023, sequential anti-SARS-CoV-2 spike IgG titers were determined in 45 patients with CLD who received two or three doses of COVID-19 vaccine. The geometric mean of anti-spike IgG at four weeks after the second and third doses were 1313.16 BAU/mL and 3042.29 BAU/mL, respectively, and it decreased significantly from four to 24 weeks after the second (1313.16 vs. 198.42 BAU/mL, p = 0.002) and the third (3042.29 vs. 636.71 BAU/mL, p < 0.001) dose. The anti-spike IgG titers in participants receiving prime-boost homologous mRNA vaccines (BNT162b2 or mRNA-1273) were comparable between participants with and those without significant liver fibrosis at each follow-up time point. This study demonstrated a notable decrease in anti-spike IgG after completion of the vaccination schedule in patients with CLD, highlighting the importance of additional booster doses.

Outcomes of COVID-19 in 24 hospitalized liver transplant recipients: an observational study

BACKGROUND

Although liver transplant (LT) recipients are considered a population at risk of severe features of coronavirus disease 2019 (COVID-19), data in this regard are scarce and controversial. In this study, we reported the outcome of 24 cases of LT recipients who were hospitalized due to COVID-19 and investigated the role-playing factors in the severity of the disease.

METHODS

In this single-center, analytic case-series study, eligible patients were among LT recipients who were hospitalized due to the diagnosis of COVID-19 based on positive results of polymerase chain reaction. Participants were categorized as severe COVID-19 if they were admitted to the intensive care unit, experienced respiratory failure demanding mechanical ventilation, or eventually died. Demographic and clinical data, COVID-19 symptoms and specific treatments, laboratory biomarkers, and immunosuppressive regimens and their alteration during the admission were recorded. Analysis was done using SPSS software.

RESULTS

Twenty-four hospitalized LT patients were included, of which nine had severe and fifteen had non-severe COVID-19. Out of 9 patients with severe COVID-19, four sadly died. The analysis and comparison between the two groups revealed longer hospital stays (P = 0.02), lower lymphocyte counts (P = 0.002), and higher levels of C-reactive protein (CRP) (P = 0.006) in patients with severe COVID-19. Patients with non-severe COVID-19 had higher doses of tacrolimus and mycophenolate in their baseline immunosuppressive regimen (both P = 0.02).

CONCLUSION

Lymphopenia and high CRP levels are associated with more severe forms of COVID-19 in LT patients. Mycophenolate may have protective properties against severe COVID-19. The role of severity indicators in LT patients with COVID-19 needs to be systematically recognized.

Risk of Corneal Transplant Rejection Following COVID-19 Vaccination: A Systematic Review and Meta-analysis

INTRODUCTION

The COVID-19 pandemic has initiated an unparalleled global vaccination campaign, raising concerns about the vaccine's effects on various health conditions, including the risk of corneal transplant rejection. This systematic review aimed to identify the relationship between COVID-19 vaccination and rejection of corneal transplant, filling a significant gap in the existing medical literature.

METHODS

A literature search was performed across multiple databases up to February 12, 2024, to identify studies evaluating the risk of corneal transplant rejection post-COVID-19 vaccination. Eligible studies were original research that reported outcomes of corneal graft rejection following vaccination. Nested Knowledge web software facilitated screening and data extraction. The Newcastle-Ottawa Scale was employed for quality assessment. A meta-analysis was conducted to calculate the aggregated relative risk (RR) utilizing R software version 4.3.

RESULTS

Six studies were included in the qualitative synthesis, with four meeting the criteria for meta-analysis. These studies varied in geographic location, surgical techniques, and types of vaccines used. The pooled RR for corneal transplant rejection following COVID-19 vaccination was 0.816 (95% CI 0.178-1.453), indicating no significant risk of rejection. No statistical heterogeneity was observed among the studies (I2 = 0%).

CONCLUSIONS

This review and meta-analysis found no significant evidence that COVID-19 vaccination increases the risk of corneal graft rejection. However, the current evidence is insufficient to conclusively determine the vaccine's safety for corneal transplant recipients. These findings underscore the need for additional research to confirm these preliminary results and investigate the long-term effects of COVID-19 vaccination on corneal transplants, aiming to provide evidence-based guidance to healthcare providers and patients.

Efficacy, immunogenicity, and safety of COVID-19 vaccines in individuals with liver cirrhosis: a rapid review and meta-analysis

The emergence of coronavirus disease 2019 (COVID-19) vaccines has been a remarkable advancement. However, the efficacy, immunogenicity, and safety of these vaccines in individuals with liver cirrhosis require careful evaluation due to their compromised immune status and potential interactions with underlying liver disease. The present study aimed to evaluate the safety and efficacy of COVID-19 vaccines in liver cirrhosis patients. In the present study, we searched international databases, including Google Scholar, PubMed, Scopus, Embase, and Web of Science. The search strategy was carried out by using keywords and MeSH (Medical Subject Headings) terms. STATA ver. 15.0 (Stata Corp., USA) was used to analyze the data statistically. The analysis was performed using the random-effects model. We also used the chi-square test and I2 index to calculate heterogeneity among studies. For evaluating publication bias, Begg's funnel plots and Egger's tests were used. A total of 4,831 liver cirrhosis patients with COVID-19 were examined from 11 studies. The rate of hospitalization in the patients with liver cirrhosis was 17.6% (95% confidence interval [CI], 9%-44%). The rate of fever in the patients with liver cirrhosis was 4.5% (95% CI, 0.9%-8.1%). The rate of positive neutralizing antibodies in the patients with liver cirrhosis was 82.5% (95% CI, 69.8%-95.1%). Also, the rates of seroconversion after the second vaccination in patients with liver cirrhosis and the control group were 96.6% (95% CI, 92.0%-99.0%), and 99.7% (95% CI, 99.0%-100.0%), respectively. COVID-19 vaccines have demonstrated promising efficacy, immunogenicity, and safety profiles in individuals with liver cirrhosis, providing crucial protection against COVID-19-related complications.

Immune responses and clinical outcomes after COVID-19 vaccination in patients with liver disease and liver transplant recipients

BACKGROUND & AIMS

Comparative assessments of immunogenicity following different COVID-19 vaccines in patients with distinct liver diseases are lacking. SARS-CoV-2-specific T-cell and antibody responses were evaluated longitudinally after one to three vaccine doses, with long-term follow-up for COVID-19-related clinical outcomes.

METHODS

A total of 849 participants (355 with cirrhosis, 74 with autoimmune hepatitis [AIH], 36 with vascular liver disease [VLD], 257 liver transplant recipients [LTRs] and 127 healthy controls [HCs]) were recruited from four countries. Standardised immune assays were performed pre and post three vaccine doses (V1-3).

RESULTS

In the total cohort, there were incremental increases in antibody titres after each vaccine dose (p <0.0001). Factors associated with reduced antibody responses were age and LT, whereas heterologous vaccination, prior COVID-19 and mRNA platforms were associated with greater responses. Although antibody titres decreased between post-V2 and pre-V3 (p = 0.012), patients with AIH, VLD, and cirrhosis had equivalent antibody responses to HCs post-V3. LTRs had lower and more heterogenous antibody titres than other groups, including post-V3 where 9% had no detectable antibodies; this was heavily influenced by intensity of immunosuppression. Vaccination increased T-cell IFNγ responses in all groups except LTRs. Patients with liver disease had lower functional antibody responses against nine Omicron subvariants and reduced T-cell responses to Omicron BA.1-specific peptides compared to wild-type. 122 cases of breakthrough COVID-19 were reported of which 5/122 (4%) were severe. Of the severe cases, 4/5 (80%) occurred in LTRs and 2/5 (40%) had no serological response post-V2.

CONCLUSION

After three COVID-19 vaccines, patients with liver disease generally develop robust antibody and T-cell responses to vaccination and have mild COVID-19. However, LTRs have sustained no/low antibody titres and appear most vulnerable to severe disease.

IMPACT AND IMPLICATIONS

Standardised assessments of the immune response to different COVID-19 vaccines in patients with liver disease are lacking. We performed antibody and T-cell assays at multiple timepoints following up to three vaccine doses in a large cohort of patients with a range of liver conditions. Overall, the three most widely available vaccine platforms were immunogenic and appeared to protect against severe breakthrough COVID-19. This will provide reassurance to patients with chronic liver disease who were deemed at high risk of severe COVID-19 during the pre-vaccination era, however, liver transplant recipients had the lowest antibody titres and remained vulnerable to severe breakthrough infection. We also characterise the immune response to multiple SARS-CoV-2 variants and describe the interaction between disease type, severity, and vaccine platform. These insights may prove useful in the event of future viral infections which also require rapid vaccine development and delivery to patients with liver disease.

Dynamic Humoral Immune Response to Primary and Booster Inactivated SARS-CoV-2 Vaccination in Patients with Cirrhosis

Background and Aims

Our aim was to determine the immune efficacy of a severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) booster vaccination in cirrhotic patients who had received the primary series.

Methods

We performed a longitudinal assessment in 48 patients with cirrhosis, 57 patients with chronic hepatitis B (CHB) and 68 healthy controls (HCs) to continuously track the dynamics of SARS-CoV-2 specific antibodies and memory B cells after receiving the primary series and booster dose at different times. A pseudovirus neutralization assay was used to determine neutralization against Omicron subvariants BA.2.12.1, BA.4 and BA.5 from serum samples collected from three cohorts.

Results

Serum anti-receptor-binding domain (RBD) immunoglobulin (Ig)G and neutralizing antibody (NAb) levels in cirrhotic patients were elevated within 15-45 days after completing the primary series before rapidly declining and reaching a valley at around 165-195 days. After receiving the booster dose, both antibody levels were significantly increased to levels comparable to patients with CHB and HCs. Subgroup analysis showed that booster vaccination induced weaker antibody responses in patients with decompensated cirrhosis than in those with compensated cirrhosis. The SARS-CoV-2 memory B-cell response in cirrhotic patients was durable during follow-up regardless of the hepatic fibro-cirrhosis grade. However, compared with the primary series, the booster dose did not result in an evident improvement of neutralization activity against the Omicron subvariants BA.2.12.1 and BA.4, and was followed by a significant decrease in the titer against BA.5.

Conclusions

A booster dose elicited a robust and durable humoral response to the wild-type strain in cirrhotic patients but not the Omicron subvariants. Repeated vaccination of inactivated SARS-CoV-2 vaccine may not benefit cirrhotic patients in neutralization against newly circulating strains.

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.

Factors influencing immunogenicity and safety of SARS-CoV-2 vaccine in liver transplantation recipients: a systematic review and meta-analysis

Background

This review summarizes the factors influencing the efficacy and safety of the COVID-19 vaccine in LTR through meta-analysis, hoping to provide strategies for vaccine use.

Methods

Electronic databases were screened for studies on mRNA vaccines in LTR. The primary outcome was the pooled seroconversion rate, and the secondary outcome was the incidence of adverse events+breakthrough infections. Subgroup analyses were made based on BMI, associated comorbidities, presence of baseline leukopenia, time since transplant, and drugs used.

Result

In total, 31 articles got included. The pooled seroconversion rate after at least two doses of SARS-CoV-2 vaccination was 72% (95% CI [0.52-0.91). With significant heterogeneity among studies I2 = 99.9%, the seroconversion rate was about 72% (95%CI [0.66-0.75]), from the studies reporting two doses of vaccine slightly higher around 75%(95%CI [0.29-1.22]) from studies reporting three doses. The pooled seroconversion rate within the lower to normal BMI group was 74% (95% CI [0.22-1.27], Pi=0.005) against 67% (95% CI [0.52-0.81], Pi=0.000) in the high BMI group. The pooled seroconversion rate in the ''positive leukopenia'' group was the lowest, 59%. Leukopenia could influence the vaccine seroconversion rate in LTR. From the time since transplant analysis after setting seven years as cut off point, the pooled seroconversion rate after at least two doses of COVID-19 vaccination was 53% (95% CI [0.18-0.83], P=0.003, I2 = 99.6%) in <7years group and 83% (95% CI [0.76-0.90], P=0.000 I2 = 95.7%) in > 7years group. The only time since transplantation had reached statistical significance to be considered a risk factor predictor of poor serological response (OR=1.27 95%CI [1.03-1.55], P=0.024). The breakthrough infection rate after vaccination was very low2% (95% CI 0.01-0.03, I2 = 63.0%), and the overall incidence of adverse events, which included mainly pain at the injection site and fatigue, was 18% (95%CI [0.11-0.25], I2 = 98.6%, Pi=0.000).

Conclusion

The seroconversion rate in LTR vaccinated with at least two doses of mRNA COVID-19 vaccine could be significantly affected by the vaccine type, immunosuppressant used, BMI, leukopenia, associated comorbidities, and time since transplantation. Nevertheless, booster doses are still recommended for LTR.

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.

COVID-19 in patients with liver disease and liver transplant: clinical implications, prevention, and management

The coronavirus disease 2019 (COVID-19) pandemic has had enormous implications for the care of patients with chronic liver disease (CLD), cirrhosis, and liver transplant (LT). Clinical outcomes of COVID-19 vary in patients with CLD and cirrhosis compared to healthy controls, and in patients with LT compared to patients without LT. Several special considerations apply to the approach to vaccination and treatment in patients with CLD and LT. The practice of liver transplantation has also been heavily impacted by the pandemic, including persistent reductions in living donor LT and increases in LT for an indication of alcohol-related liver disease. Recent medical society guidelines strive to standardize severe acute respiratory syndrome coronavirus 2 testing in donors and recipients and the approach to transplantation after recovered from COVID-19 infection, but certain controversies remain.

COVID‑19 vaccination in liver transplant recipients (Review)

Severe acute respiratory syndrome coronavirus 2 (Sars-CoV-2) infection has significantly affected immunocompromised individuals and subsequently, liver transplant recipients (LTRs). Early in the course of pandemic, this vulnerable population was prioritized for vaccination, after obtaining encouraging data about the vaccination benefits on disease severity and mortality. As the published knowledge was mainly supported from studies which were limited to the healthy population, the present review summarizes the data from the literature on coronavirus disease 2019 (COVID-19) vaccination in LTRs and the available vaccination guidelines of international societies. The COVID-19 vaccination of LTRs is strongly recommended as a safe and effective measure in order to prevent severe disease and mortality.

COVID-19 and liver injury: Pathophysiology, risk factors, outcome and management in special populations

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 is an ongoing health concern. In addition to affecting the respiratory system, COVID-19 can potentially damage other systems in the body, leading to extra-pulmonary manifestations. Hepatic manifestations are among the common consequences of COVID-19. Although the precise mechanism of liver injury is still questionable, several mechanisms have been hypothesized, including direct viral effect, cytokine storm, hypoxic-ischemic injury, hypoxia-reperfusion injury, ferroptosis, and hepatotoxic medications. Risk factors of COVID-19-induced liver injury include severe COVID-19 infection, male gender, advanced age, obesity, and underlying diseases. The presentations of liver involvement comprise abnormalities in liver enzymes and radiologic findings, which can be utilized to predict the prognosis. Increased gamma-glutamyltransferase, aspartate aminotransferase, and alanine aminotransferase levels with hypoalbuminemia can indicate severe liver injury and anticipate the need for intensive care units’ hospitalization. In imaging, a lower liver-to-spleen ratio and liver computed tomography attenuation may indicate a more severe illness. Furthermore, chronic liver disease patients are at a higher risk for severe disease and death from COVID-19. Nonalcoholic fatty liver disease had the highest risk of advanced COVID-19 disease and death, followed by metabolic-associated fatty liver disease and cirrhosis. In addition to COVID-19-induced liver injury, the pandemic has also altered the epidemiology and pattern of some hepatic diseases, such as alcoholic liver disease and hepatitis B. Therefore, it warrants special vigilance and awareness by healthcare professionals to screen and treat COVID-19-associated liver injury accordingly.

Effectiveness of vaccination against SARS-CoV-2 and the need for alternative preventative approaches in immunocompromised individuals: a narrative review of systematic reviews

INTRODUCTION

Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including administration of booster doses, continues to be the most effective method for controlling COVID-19-related complications including progression to severe illness and death.However, there is mounting evidence that more needs to be done to protect individuals with compromised immune function.

AREAS COVERED

Here, we review the effectiveness of COVID-19 vaccination in immunocompromised patients, including those with primary immunodeficiencies, HIV, cancer (including hematological malignancies), solid organ transplant recipients and chronic kidney disease, as reported in systematic reviews/meta-analyses published over a 12-month period in PubMed. Given the varied responses to vaccination patients with compromised immune function, a major goal of this analysis was to try to identify specific risk-factors related to vaccine failure.

EXPERT OPINION

COVID-19 remains a global problem, with new variants of concern emerging at regular intervals. There is an ongoing need for optimal vaccine strategies to combat the pandemic. In addition, alternative treatment approaches are needed for immunocompromised patients who may not mount an adequate immune response to current COVID-19 vaccines. Identification of high-risk patients, and the introduction of newer antiviral approaches such as monoclonal antibodies, will offer physicians therapeutic options for such vulnerable individuals.

Challenges in liver transplantation in the context of a major pandemic

Coronavirus disease-2019 (COVID-19) has led to a temporary suspension of liver transplant activity across the world and the remodeling of care for patients on the waiting list and transplant recipients with the increasing use of remote consultations. Emerging evidence shows that patients with more advanced liver disease are at increased risk of severe COVID-19 and death, whereas transplant recipients have similar risk with the general population which is mainly driven by age and metabolic comorbidities. Tacrolimus immunosuppression might have a protective role in the post-transplant population. Vaccines that have become rapidly available seem to be safe in liver patients, but the antibody response in transplant patients is likely suboptimal. Most transplant centers were gradually able to resume activity soon after the onset of the pandemic and after modifying their pathways to optimize safety for patients and workforce. Preliminary evidence regarding utilizing grafts from positive donors and/or transplanting recently recovered or infected recipients under certain circumstances is encouraging and may allow offering life-saving transplant to patients at the greatest need. This review summarizes the currently available data on liver transplantation in the context of a major pandemic and discusses areas of uncertainty and future challenges. Lessons learnt from the COVID-19 pandemic might provide invaluable guidance for future pandemics.