Which of the following individuals is acceptable as a blood donor?

The individual who received the hepatitis B vaccine last week is acceptable as a blood donor because vaccination against hepatitis B is encouraged and does not affect the person's eligibility to donate blood. Since the vaccine does not introduce any infectious agent into the bloodstream, the donation process remains safe for both the donor and the recipient.

In contrast, individuals who have undergone a recent body modification, such as a nose piercing, typically have a deferral period due to the risk of infection that may arise from the procedure. Likewise, someone who has lived in a region where certain diseases, such as malaria or other endemic infections, are prevalent may pose a risk of transmission, leading to deferral based on recent travel history. Lastly, a person who tested positive for hepatitis C is also deferred from donating blood due to the potential for transmitting the virus, even if they currently show no symptoms.

The safety guidelines for blood donation are in place to ensure that both the donor and recipient are protected from possible health risks.