Liver and Bile
J Hepatol. 2022;77(5):1339–48
Risk of acute liver injury following the mRNA (BNT162b2) and inactivated (CoronaVac) COVID-19 vaccines
Background and aims: Case reports of severe acute liver injury (ALI) following COVID-19 vaccination have recently been published. The authors evaluated the risks of ALI following COVID-19 vaccination (BNT162b2 or CoronaVac).
Methods: They conducted a modified self-controlled case series analysis using the vaccination records in Hong Kong with data linkage to electronic medical records from a territory-wide healthcare database. Incidence rate ratios (IRRs) for ALI outcome in the 56-day period following first and second doses of COVID-19 vaccines in comparison to the non-exposure period were estimated and compared to the ALI risk in patients with SARS-CoV-2 infection.
Results: Among 2,343,288 COVID-19 vaccine recipients who were at risk, 4677 patients developed ALI for the first time between February 23, 2021, to September 30, 2021. The number of ALI cases within 56 days after the first and second dose of vaccination were 307 and 521 (335 and 334 per 100,000 person-years) for BNT162b2, and 304 and 474 (358 and 403 per 100,000 person-years) for CoronaVac, respectively, compared to 32,997 ALI cases per 100,000 person-years among patients within 56 days of SARS-CoV-2 infection. Compared to the non-exposure period, no increased risk was observed in the 56-day risk period for first (IRR = 0.800; 95% confidence interval [CI]: 0.680–0.942) and second (IRR = 0.944; 95% CI: 0.816–1.091) dose of BNT162b2, or first (IRR = 0.689; 95% CI: 0.588–0.807) and second (IRR = 0.905; 95% CI: 0.781–1.048) dose of CoronaVac. There were no severe or fatal cases of ALI following COVID-19 vaccination.
Conclusion: There was no evidence of an increased risk of acute liver injury (ALI) associated with BNT162b2 or CoronaVac vaccination. Based on all current available evidence from previous studies and this study, the benefit of mass vaccination far outweighs the ALI risk from vaccination.