Adjuvant used in DPT vaccine:
**Core Concept**
The DPT vaccine is a combination vaccine that protects against diphtheria, pertussis, and tetanus. The vaccine contains inactivated or attenuated antigens of the respective pathogens. An adjuvant is a substance added to vaccines to enhance the immune response.
**Why the Correct Answer is Right**
Aluminum salts, specifically aluminum phosphate or aluminum hydroxide, are commonly used adjuvants in DPT vaccines. These adjuvants work by activating the immune system's dendritic cells, which then present the antigens to T-cells, stimulating an immune response. The addition of adjuvants increases the vaccine's efficacy by enhancing the production of antibodies against the pathogens.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because aluminum salts are the primary adjuvants used in DPT vaccines, not mercury-containing preservatives.
* **Option B:** This option is incorrect because squalene is an adjuvant used in certain influenza vaccines, not DPT vaccines.
* **Option C:** This option is incorrect because polysorbate 80 is an emulsifier used in some vaccines, but not a primary adjuvant in DPT vaccines.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that adjuvants can cause local reactions, such as redness, swelling, or pain at the injection site. However, these reactions are typically mild and resolve on their own.
**Correct Answer: C. Aluminum salts.**