A third dose of the BNT162b2 mRNA vaccine sufficiently improves the neutralizing activity against SARS-CoV-2 variants in liver transplant recipients.

Introduction: We examined the neutralizing antibody production efficiency of the second and third severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine doses (2nd- and 3rd-dose) and neutralizing activity on mutant strains, including, the Ancestral, Beta and Omicron strains using green fluorescent protein-carrying recombinant SARS-CoV-2, in living-donor liver transplantation (LDLT) recipients. Methods: The patients who were administered vaccines other than Pfizer- BioNTechBNT162b2 and who had coronavirus disease 2019 in this study period were excluded. We enrolled 154 LDLT recipients and 50 healthy controls. Result: The median time were 21 days (between 1st and 2nd vaccination) and 244 days (between 2nd and 3rd vaccination). The median neutralizing antibody titer after 2nd-dose was lower in LDLT recipients than in controls (0.46 vs 1.00, P<0.0001). All controls had SARS-CoV-2 neutralizing antibodies, whereas 39 LDLT recipients (25.3%) had no neutralizing antibodies after 2nd-dose; age at vaccination, presence of ascites, multiple immunosuppressive treatments, and mycophenolate mofetil treatment were significant risk factors for nonresponder. The neutralizing activities of recipient sera were approximately 3-fold and 5-fold lower than those of control sera against the Ancestral and Beta strains, respectively. The median antibody titer after 3rd-dose was not significantly different between recipients and controls (1.02 vs 1.22, p=0.0758); only 5% recipients was non-responder. The neutralizing activity after third dose to Omicron strains were enhanced and had no significant difference between two groups. Conclusion: Only the 2nd-dose was not sufficiently effective in recipients; however, 3rd-dose had sufficient neutralizing activity against the mutant strain and was as effective as that in healthy controls.

Trends in hepatocellular carcinoma incident cases in Japan between 1996 and 2019.

We examined the epidemiological trends, including the distribution of sex, age, and disease etiology, in HCC incident cases, over 24 years. Data of 20,547 HCC patients (1996-2019) were analyzed in this prospective study. We divided the study period into four 6-yearly quarters. HCC etiology was categorized as hepatitis B virus (HBV) infection, HBV + hepatitis C virus (HCV) infection, HCV infection, and both negative (non-BC). The incident cases of HCC per quarter of the study period were 4311 (21.0%), 5505 (26.8%), 5776 (28.1%), and 4955 (24.1%), sequentially. Overall, 14,020 (68.2%) patients were male. The number of HCC cases in patients < 60 years, 60-69 years, 70-79 years, and ≥ 80 years were 3711 (18.1%), 6652 (32.4%), 7448 (36.2%), and 2736 (13.3%), respectively. The average age of newly-diagnosed patients increased in each quarter. HCC was associated with HBV, HBV + HCV, and HCV infections and non-BC in 2997 (14.6%), 187 (0.9%), and 12,019 (58.5%), and 5344 (26.0%) cases, respectively. The number of HCV-associated cases decreased in each quarter, while that of non-BC-associated cases increased. HCC incident cases tend to increase in the elderly and in non-BC patients; in contrast, HCC incident cases due to HCV tend to decrease.