Weaker SARS-CoV-2 vaccine responses in nonalcoholic fatty liver disease with advanced liver fibrosis

BACKGROUND: SARS-CoV-2 vaccine responses that could harbor potential risks to chronic liver diseased patients. AIMS: To assess immune response following Pfizer's SARS-CoV-2 vaccine in patients with different liver fibrosis severities of nonalcoholic fatty liver disease (NAFLD). METHODS: Clinical and histological (NAS-score and fibrosis stage) characteristics of NAFLD patients before vaccine were correlated with serologic vaccine responses of two doses of the BNT162b2. Serum SARS-CoV-2 spike immunoglobulins (anti-S) were assessed on day seven following immunization (Liaison assay). RESULTS: The mean-age of patients (n = 157) was 56.9 ± 13.2 years (46.5 % males). 94.8 % had a positive response (anti-S levels ≥ 19 AU/ml). The anti-S cutoff of 200 AU/ml used to separate strong vs. weak responses. A strong response (anti-S titers ≥ 200 AU/ml) was observed in 93/157 (59.2 %) patients with a mean-age of 53.1 ± 13.8 years (45.2 % males). A weak response (anti-S titers < 200 AU/ml) was observed in 64/157 (40.8 %) cases with a mean-age of 62.3 ± 10.2 years (p < 0.0001). The strong response subgroup had lower metabolic comorbidities, including glucose hemostasis, hypertension, and dyslipidemia (p < 0.04). Moreover, the strong response subgroup had fibrosis stages F0-F2 (75.3 % vs. 56.3 %) and lower rates of advanced stages F3-F4 (24.7 % vs. 43.8 %). The F0-F2 subgroups had significantly higher rates of strong responses than the F3-F4 stages. The anti-S ≥ 200 and anti-S ≥ 400 AU/ml response achieved in 66 % and 36.8 % of the F0-F2 population was significantly higher than the 45.1 % (p = 0.006) and 23.5 % (p = 0.05) in the F3-F4 population, respectively. The Fib-4 calculations and Fibroscan evaluations were consistent with histologic fibrosis assessment. CONCLUSION: Advanced liver fibrosis (assessed by histology, Fib-4, or Fibroscan) is a risk factor for lower response to Pfizer's BNT162b2 vaccine, and patients should be prioritized for the vaccine booster against SARS-CoV-2.