Sars-Cov-2 vaccination in liver transplant recipients: The 'holy grail' in a hostile environment

Immune Response to SARS-CoV-2 XBB.1.5 and JN.1 Variants Following XBB.1.5 Booster Vaccination in Liver Transplant Recipients

BACKGROUND/OBJECTIVES

The efficacy of monovalent BNT162b2 Omicron XBB.1.5 booster vaccination in liver transplant recipients (LTRs) has yet to be described, particularly regarding the immune response to emerging variants like JN.1.

METHODS

This study evaluated humoral and cellular immune responses in 34 liver transplant recipients (LTRs) with varying SARS-CoV-2 immune histories before and after receiving a BNT162b2 Omicron XBB.1.5 booster vaccination. The assessment involved variant-specific serology, pseudovirus neutralization tests, and Interferon-γ release assays.

RESULTS

Participants had a median of four prior vaccinations, with 91.2% having a history of infection. Post-vaccination, significant increases in both Wuhan anti-S and Omicron-specific IgG antibodies and improved neutralization of B.1, XBB.1.5, and JN.1 pseudovirus particles were observed. Also, T-cell responses significantly increased post-vaccination. However, 17.6% of LTRs had no neutralizing antibodies against XBB.1.5 and JN.1, while 100% of healthy controls did. Shortly after vaccination, 18% of patients developed mild COVID-19. These LTRs had particularly low immune responses at baseline.

CONCLUSIONS

The monovalent XBB.1.5 booster improved overall SARS-CoV-2-specific immunity. However, some LTRs still showed low or undetectable immune responses, indicating that ongoing monitoring and further booster doses are necessary in this high-risk group.

Clinical Outcomes of SARS-CoV-2 Breakthrough Infections in Liver Transplant Recipients during the Omicron Wave

At the start of the pandemic, liver transplant recipients (LTR) were at high risk of developing severe COVID-19. Here, the outcomes of breakthrough infections in fully vaccinated LTR (n = 98) during the Omicron wave were assessed. In most patients, a mild disease course was observed, but 11 LTR (11.2%) required hospitalization for COVID-19-related complications. All patients survived. The LTR requiring hospitalization were older (67 years vs. 54 years; p < 0.001), had a higher Charlson comorbidity index (9 vs. 5; p < 0.001), and a lower anti-S RBD titer (Roche Elecsys) prior to infection (508.3 AU/mL vs. 2044 AU/mL; p = 0.03). Long-lasting symptoms for ≥4 weeks were reported by 37.5% of LTR (30/80). Risk factors in LTR included female sex (p = 0.01; Odds Ratio (OR) = 4.92 (95% confidence interval (CI) (1.5-16.5)) and dyspnea (p = 0.009; OR = 7.2 (95% CI (1.6-31.6)) during infection. Post-infection high anti-S RBD antibody levels were observed in LTR, and healthy controls (HC), while the cellular immune response, assessed by interferon-gamma release assay (EUROIMMUN), was significantly lower in LTR compared with HC (p < 0.001). In summary, in fully vaccinated LTR, SARS-CoV-2 breakthrough infections during the Omicron wave led to mild disease courses in the majority of patients and further boosted the humoral and cellular hybrid anti-SARS-CoV-2-directed immune response. While all patients survived, older and multimorbid LTR with low baseline antibody titers after vaccination still had a substantial risk for a disease course requiring hospitalization due to COVID-19-related complications.

COVID-19-associated liver injury, role of drug therapy and management: a review

The ongoing COVID-19 pandemic is known to affect several body organs, including the liver. This results from several factors such as direct effect of SARS-CoV-2 on the liver, side effects of drug therapy and pre-existing liver diseases. Drug-induced liver injury can result from a range of drugs used in the treatment of COVID-19 such as antiviral drugs, anti-inflammatory drugs, antibiotics, herbal medications and vaccines. Metabolism of most drugs occurs in the liver, and this leaves the liver at risk of medication-induced liver damage. Being among pathologies from the disease, COVID-19 liver injury presents with abnormally high liver-related enzymes, such as aspartate aminotransferase, alanine aminotransferase, alkaline phosphate (ALP), and gamma-glutamyl transferase. It is reversible, generally not severe and occurs more mildly in children. However, COVID-19-associated liver injury is worsened by chronic liver diseases and vice versa. There is a high risk of abnormal ALT and AST, in-hospital liver injury and prolonged SARS-CoV-2 shedding in COVID-19 patients with previously existing metabolic-associated fatty liver disease. COVID-19-associated liver injury also appears to be severe and significantly associated with life-threatening COVID-19 and mortality in persons with a history of liver transplant. Where necessary, only supportive management is usually indicated. This paper evaluates the aetiology, clinical and laboratory features, occurrence and management of COVID-19-associated liver injury. It also elaborated on the role of drug therapy in the development of COVID-19 liver injury.

Omicron infections profile and vaccination status among 1881 liver transplant recipients: a multi-center retrospective cohort

BACKGROUND & AIMS

A wave of Omicron infections rapidly emerged in China in 2022, but large-scale data concerning the safety profile of vaccines and Coronavirus disease 2019 (COVID-19) infection features in liver transplant (LT) recipients have not been collected. Therefore, the aim of this study was to assess the protectiveness and safety profile of the inactivated vaccines in LT patients against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infections.

METHODS

A multi-center retrospective study was conducted in a cohort with a history of liver transplantation. Electronic questionnaires were used to collect data on demographics, vaccination information, history of liver transplantation, and characteristics of COVID-19 infection until June 2022. The vaccine information included number of doses, vaccine type, injection time, and adverse events.

RESULTS

A total of 1881 participants (487 vaccinated and 1394 unvaccinated patients) were enrolled from seven centers in China. Fourteen of the participants were infected by Omicron, and 50% patients had over 14 days of viral shedding duration. The protection rate of COVID-19 vaccinations to Omicron was 2.59%. The three breakthrough infections occurred more than 6 months after fully vaccinated. A total of 96 (19.7%) vaccinated patients had adverse events, including fatigue, myalgia, liver dysfunction, swelling, and scleroma. There were more Grade 3 adverse events in the preoperative vaccination group than those in the postoperative vaccination group.

CONCLUSION

Inactivated whole-virion SARS-CoV-2 vaccines are safe in patients with post-liver transplantation. The efficacy of inactivated vaccines decreases after 6 months of vaccination, it is recommended that liver transplant patients get boosted vaccinations as early as possible even when they are fully vaccinated. Although clinical manifestations of Omicron infections were mild in LT patients, unvaccinated patients might have a higher risk of liver dysfunction during infections.