The hepatitis B vaccine may be associated with an increased risk of developing oral lichen planus, a chronic inflammatory condition that affects the mouth, or lesions that mimic the condition, according to a large study recently published in BMC Oral Health.
However, the results should be construed as hypothesis-generating and therefore warrant further prospective studies, the authors wrote.
“This study demonstrates a statistically significant but modestly increased risk of OLP/OLL (oral lichen planus/oral lichenoid lesions) following hepatitis B vaccination,” Dr. Saskia Preissner of Charité University Medicine Berlin in Germany said (BMC Oral Health, August 26, 2025, Vol. 25, 1378).
OLP is an ongoing condition that is not contagious and can cause painful sores, white patches, and lacy streaks in the mouth. The exact cause of the condition is not clear. It occurs when a person’s immune system mistakenly attacks cells in the mouth. OLL is a cluster of inflammatory conditions that imitate OLP. The lesions are externally triggered by dental materials, medication, and other materials and factors.
Although the hepatitis B shot is considered safe, isolated cases have suggested a potential correlation between the vaccine and OLP, according to the study.
To investigate a potential association between the vaccine and both oral conditions, a matched cohort study was conducted using the TriNetX database, a network of data collected by the software company TriNetX LLC in partnership with healthcare providers.
The study was conducted with data from 112,444 patients who received the hepatitis B vaccination and 112,444 who did not receive the shot. The primary outcome was developing OLP within 30 days post-index, identified by the International Classification of Diseases (ICD-10) codes and confirmed via histological examination, according to the study.
OLP/OLLs occurred in 423 vaccinated patients and in 316 unvaccinated individuals with a significant group difference (p < 0.001). Furthermore, the risk ratio was 1.400 (95% confidence interval [CI], 1.210 to 1.619), and the odds ratio was 1.401 (95% CI, 1.211 to 1.622), the authors wrote.
There were several limitations. Due to the nature of the study, residual confounding factors can’t be excluded. Factors like oral hygiene products that can affect OLP risk were not part of this study’s dataset, they wrote.
Therefore, prospective studies with very thorough diagnostic criteria and comprehensive control of local and systemic confounders are needed to better understand the potential role of hepatitis B vaccination in the pathogenesis of OLP, the authors wrote.
“In this large-scale real-world data analysis, a statistically significant association was observed between hepatitis B vaccination and the onset of OLP or OLL,” Preissner and colleagues wrote.
