By Craig Lammert, M.D., AIHA Executive Director

Over the past year, a few members of the Autoimmune Hepatitis Association (AIHA) have emailed us or shared in our virtual support groups that they are concerned the SARS-CoV-2 vaccines may have triggered their autoimmune hepatitis (AIH). A few published reports of few patients developing AIH after COVID vaccines have also left doctors and patients wondering if there is a solid link.

While there is still much to learn, some recent data published this week in the Journal of Hepatology from Indiana University (IU) and Germany provides more clarity. Overall, both studies suggest that if COVID-19 vaccines can trigger AIH, it is likely to be a very very rare event. This should be reassuring to patients and doctors alike that the COVID-19 vaccines continue to be safe.

The IU study focused on 470,274 people that had at least one dose of a SARS-CoV-2 vaccine and no pre-existing liver disease. Among these, 177 (0.038%) had significant liver injury (according to specified lab data) within 12 weeks of vaccine. The study also compared the rate of liver injury after COVID-19 vaccines to liver injury seen after flu vaccine in 2019, when SARS-CoV-2 still had not been detected in the US. Liver injury with flu vaccine within 12 weeks of vaccine was observed, but also very rare (15 out of 130,067 people: 0.069%).

In the German study of a large liver center, the authors found new patients with an AIH diagnosis were fewer in 2020 and 2021 compared to prior years. This is despite the widespread use of COVID-19 vaccines during these years. The authors were able to look more closely at 25 of the 33 newly diagnosed AIH patients during this time. Among these, only five were diagnosed within two to 18 weeks of the first or second COVID-19 vaccine dose. Most importantly, four of these (80%) had features that suggested they had preexisting liver disease prior to vaccination. Therefore, the vaccine could not have triggered AIH if it was likely already there (but undiagnosed).

Both the IU and German study authors both felt these two studies strongly supported that COVID-19 vaccine does not induce autoimmune hepatitis. Yet, both are careful to say it could be possible in rare cases and further investigation is warranted.