Hepatitis B vaccination is given to a patient. His serum will reveal –
**Core Concept**
The hepatitis B vaccination induces an immune response, leading to the production of antibodies against the hepatitis B virus. This is a result of the introduction of a non-infectious, recombinant DNA vaccine or an inactivated vaccine, which stimulates the body's immune system to produce **antibodies**. The primary goal is to develop immunity against the **hepatitis B surface antigen (HBsAg)**.
**Why the Correct Answer is Right**
After receiving the hepatitis B vaccination, the patient's serum will contain **anti-HBs (antibodies to hepatitis B surface antigen)**, indicating immunity to hepatitis B. This is because the vaccine contains the HBsAg, which triggers the production of anti-HBs. The presence of anti-HBs is a marker of successful vaccination and provides protection against future infections.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because HBsAg is the surface antigen of the hepatitis B virus itself, not the antibody produced in response to vaccination.
**Option C:** Incorrect because **anti-HBc (antibodies to hepatitis B core antigen)** are typically seen in individuals who have been infected with hepatitis B, not in those who have been vaccinated.
**Option D:** Incorrect as it does not relate to the specific immune response generated by the hepatitis B vaccine.
**Clinical Pearl / High-Yield Fact**
It's crucial to remember that the presence of **anti-HBs** in a patient's serum indicates immunity to hepatitis B, either from vaccination or past infection. This is a key point in assessing a patient's risk and determining the need for vaccination or other preventive measures.
**Correct Answer:** D. anti-HBs.