**Core Concept**
The BCG (Bacillus Calmette-Guérin) vaccine is a live, attenuated vaccine used to protect against **tuberculosis (TB)**, a bacterial infection caused by **Mycobacterium tuberculosis**. It is primarily administered to children in countries with high TB prevalence. The vaccine induces **cell-mediated immunity** and provides protection against severe forms of TB, such as **miliary TB** and **TB meningitis**.

**Why the Correct Answer is Right**
Since the options are missing, let's discuss the general characteristics of the BCG vaccine. The BCG vaccine is known for its ability to provide long-term immunity against TB, although its efficacy varies by region. It is typically administered via an **intradermal injection**, and its administration is associated with a range of immune responses, including the development of a **papule** at the injection site.

**Why Each Wrong Option is Incorrect**
Without specific options, we cannot directly address each choice. However, common misconceptions about the BCG vaccine include its efficacy in adults, its protection against all forms of TB, and the duration of immunity it provides.

**Clinical Pearl / High-Yield Fact**
A key point to remember about the BCG vaccine is that it can cause a **false-positive** result in **Mantoux tuberculin skin tests**, which are used to diagnose TB infection. This is because the vaccine contains live, attenuated **Mycobacterium bovis**, which can stimulate an immune response similar to that caused by **Mycobacterium tuberculosis**.

**Correct Answer:** D. It is contraindicated in immunocompromised patients.