COVID-19 and the Liver: A 2021 Update

Catherine W. Spearman; Alessio Aghemo; Luca Valenti; Mark W. Sonderup

Disclosures

Liver International. 2021;41(9):1988-1998. 

In This Article

COVID-19 Vaccination in Patients With Liver Diseases and Liver Transplant Recipients

Up to January 2021, 235 vaccine candidates for COVID-19 had been reported, and 63 of them are currently being studied in human clinical trials. Four vaccines completed Phase 3 trials, with published reports, while 19 more vaccines are in Phase 3 studies.[100–102] Availability of vaccines will be different among countries due to differences in approval dates, reimbursement rules and temperature storage suitability, thus providing a detailed report on all Covid-19 vaccines is beyond the scope of the current manuscript. Four Covid-19 vaccines have been EMA-approved: BNT162b2 mRNA (BioNTech and Pfizer), mRNA-1273 (Moderna and National Institute of Allergy and Infectious Diseases – NIAID), ChAdOx1 nCoV-19 (AstraZeneca and University of Oxford) and Ad26.COV2-S [recombinant] (Johnson & Johnson).

Safety and efficacy data for patients with liver disease are limited. In the BNT162b2 mRNA vaccination study, 217 (0.6%) of 37 706 participants had liver disease, and only three (<0.1%) had moderate-to-severe liver disease. A small number of patients with liver disease were included in the Moderna trial (196 [0.6%] of 30 351), while the ChAdOx1-nCoV-19 and Ad26.COV2-S [recombinant] vaccine trials explicitly omitted patients with pre-existing liver pathology. In addition, all trials listed systemic immunosuppression as an exclusion criterion, thus preventing extrapolation of the data to immunosuppressed liver transplant recipients or patients with autoimmune liver disease.

Given the small number of patients with pre-existing liver disease included in the Phase III RCTs, the efficacy of the available vaccines cannot be ascertained. Previous studies have shown that response to vaccines is not attenuated in patients with mild–moderate liver diseases of any aetiology; however, rates of seroconversion after hepatitis B virus vaccination and the durability of humoral immunity after pneumococcal and influenza vaccination are markedly reduced in patients with cirrhosis.[103–105] Similarly, reduced immune reponse to vaccination has been reported in patients who received liver transplantation.[106] Thus, it is likely that patients with cirrhosis or those who have received liver transplantation might have attenuated immune responses to COVID-19 vaccination.[107] The recent Global Hepatology Society Statement advises that patients with liver disease including those on immunosuppression and liver transplant recipients should be vaccinated against SARS-CoV-2 with any authorized COVID-19 vaccine as the benefits outweigh the potential risks.[108–110]

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