Efficacy of mRNA vaccines on patients with liver disease

What is it about?

In early 2020, the novel coronavirus infected many people across the world. Global efforts were put into developing safe and effective vaccines against COVID-19. Between April and July 2020, newly developed mRNA vaccines were tested in clinical trials. These included the BNT162b2 mRNA COVID vaccine trial by Pfizer-BioNTech and the mRNA-1273 SARS-CoV-2 vaccine trial by the National Institute of Allergy and Infectious Diseases. In these trials, the new vaccines were well tolerated and offered up to 95% protection against COVID-19. But none of the trials included patients with advanced liver disease. In fact, only 0.6% patients in the BNT162b2 mRNA COVID vaccine trial and 0.7% patients in the mRNA-1273 SARS-CoV-2 vaccine study had diagnoses for mild forms of liver disease. Hence, how these vaccines affect patients with chronic diseases wasn’t clear. To find out how patients with chronic liver disease respond to these vaccines, a review tried to understand the effect of these vaccines on liver disease outcomes. The authors found that 6.7% and 7.8% patients in the mRNA-1273 SARS-CoV-2 vaccine trial had severe obesity and diabetes, respectively. In addition, 9.6% patients in the BNT162b2 mRNA COVID vaccine trial had diabetes. Since obesity and diabetes are risk factors of fatty liver disease, they assumed that a significant proportion of patients may have undiagnosed liver disease. These patients could also be at a high risk of developing liver disease in the future. Fortunately, the new vaccines were effective on all these patients. In contrast, for patients with severe liver diseases, vaccine efficacy was not determined.

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Photo by Jeremy Bezanger on Unsplash

Photo by Jeremy Bezanger on Unsplash

Why is it important?

Vaccines developed against COVID-19 may have negative side effects on certain populations. Patients with chronic liver diseases often have compromised immunity. Hence, they may not respond properly to these vaccines. Therefore, acquiring real-world data may help understand how these vaccines can impact patients with liver diseases. KEY TAKEAWAY: Patients with mild liver diseases may benefit from vaccines against COVID-19. For patients with advanced liver diseases, vaccine efficacy is unknown. More studies are required to understand how mRNA vaccines affect patients with liver diseases.