A hospital employee wants to donate blood three weeks after receiving the final dose of the hepatitis B vaccine. What are the expected results from her hepatitis screen, and will she be allowed to donate blood?

The correct response is that the hospital employee is expected to have a negative HBsAg and negative anti-HBc, which indicates that she is not currently infected with hepatitis B and does not have a past infection. Consequently, she is eligible to donate blood.

After receiving the hepatitis B vaccine, an individual’s body typically produces antibodies against the hepatitis B surface antigen (anti-HBs) without developing an active infection. At three weeks post-vaccination, tests for HBsAg (the hepatitis B surface antigen) and anti-HBc (antibody to the hepatitis B core antigen) would be expected to yield negative results. HBsAg positivity would indicate an active infection, while anti-HBc positivity could suggest prior infection or ongoing infection. Given that the vaccination only induces anti-HBs without producing detectable levels of anti-HBc or HBsAg, the results align with a vaccine response rather than an active infection.

Because the employee does not show any evidence of current or past hepatitis B infection based on these serological results, she meets the criteria to donate blood.