**Core Concept**
The measles vaccine is a live attenuated vaccine that, if contaminated, can cause a severe systemic reaction, including Toxic Shock Syndrome (TSS). This occurs due to the potential for the vaccine virus to mutate and become virulent, or due to the presence of bacterial contaminants such as Corynebacterium diphtheriae or Staphylococcus aureus.

**Why the Correct Answer is Right**
The measles vaccine is a live attenuated vaccine, which means it contains a weakened form of the measles virus. This type of vaccine can, in rare cases, cause a severe systemic reaction if contaminated with bacterial toxins or if the vaccine virus mutates to become virulent. The toxins produced by these bacteria can trigger a massive release of cytokines, leading to the symptoms of TSS, including fever, vomiting, diarrhea, and shock. The presence of bacterial contaminants such as Corynebacterium diphtheriae or Staphylococcus aureus in the measles vaccine can cause this severe reaction.

**Why Each Wrong Option is Incorrect**
**Option B:** The DPT vaccine is a killed-virus vaccine, which means it does not contain live bacteria or viruses and therefore cannot cause TSS.

**Option C:** The Hepatitis B vaccine is a recombinant DNA vaccine, which uses genetic material from the Hepatitis B virus to stimulate an immune response. It is not a live attenuated vaccine and therefore cannot cause TSS.

**Option D:** There is no such vaccine as the "Typhoral" vaccine. It is possible that this is a distractor or a typo, and the correct answer is the measles vaccine.

**Clinical Pearl / High-Yield Fact**
It is essential to handle live attenuated vaccines, such as the measles vaccine, with caution to prevent contamination and ensure the vaccine's potency.

**✓ Correct Answer: A. Measles vaccine**