All are true about Hepatitis B vaccine except
**Core Concept**
The Hepatitis B vaccine is a crucial tool in preventing Hepatitis B virus (HBV) infection, which can cause acute and chronic liver disease, cirrhosis, and hepatocellular carcinoma. The vaccine works by stimulating the production of antibodies against the HBV surface antigen (HBsAg), providing immunity against infection.
**Why the Correct Answer is Right**
The Hepatitis B vaccine is a recombinant DNA vaccine that uses a genetically engineered yeast cell to produce the HBsAg protein. This protein is then purified and used as the vaccine antigen. The vaccine is administered in a series of three doses, with the second dose given 1 month after the first dose and the third dose given 6 months after the first dose. The vaccine is highly effective in preventing HBV infection, with a series of doses providing long-term immunity against the virus.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the Hepatitis B vaccine is not typically given to individuals with a history of severe allergic reactions to yeast or other components of the vaccine.
* **Option B:** This option is incorrect because the Hepatitis B vaccine is not a live vaccine, making it safe for use in immunocompromised individuals.
* **Option C:** This option is incorrect because the Hepatitis B vaccine is not a single-dose vaccine; a series of three doses is required to provide long-term immunity.
**Clinical Pearl / High-Yield Fact**
The Hepatitis B vaccine is a critical component of post-exposure prophylaxis (PEP) for individuals who have been exposed to HBV through needlestick injuries, sexual contact, or other high-risk activities. Administration of the vaccine within 12 hours of exposure can provide protection against HBV infection.
**Correct Answer:** None of the above options are correct, as the question is asking for an exception to the true statements about the Hepatitis B vaccine.