Abstract
We compared the serum levels of microRNA-155 (miR-155) between subjects with normal response to hepatitis B vaccine and nonresponders. Results showed that serum expression of miR-155 was significantly higher in nonresponders than in responders (6.40 versus 2.55; Z = 2.125, P = 0.034), suggesting that overexpression of miR-155 is correlated with nonresponsiveness to hepatitis B vaccine.