Which of the following would indicate not immune to Hepatitis B?

• A. Anti-HBs negative
• B. Anti-HBs positive
• C. HBsAg negative
• D. Anti-HBc negative

Answer: (A)

Anti-HBs is the antibody that provides protection against Hepatitis B. If this antibody isn’t detectable, the person isn’t immune to HBV and would need vaccination or a booster to build protection. The absence of anti-HBs directly reflects susceptibility, which is why this option is the best indicator of not being immune.

HBsAg being negative just means there isn’t an active HBV infection at the moment; it doesn’t tell you about past immunity. Anti-HBc negative can occur in someone who has never been exposed or in someone who has been vaccinated (since the vaccine contains only HBsAg and not core antigen). So these alone don’t indicate lack of immunity as clearly as anti-HBs negativity does.