Assays for hepatitis B surface antigen (HBsAg) are the most frequently ... Beyond 14 days, there were no reactive or grayzone HBsAg tests that could be attributed to recent HBV vaccination.

If repeat Hep B surface antibody titer is non-reactive, a Hep B surface antigen test is required to rule out acute or chronic Hepatitis B infection. If Hep B surface antigen test is negative, student ...