Chicken pox vaccine is-
**Core Concept**
The chickenpox vaccine is a live, attenuated vaccine designed to protect against varicella-zoster virus (VZV) infection, which causes chickenpox and shingles. The vaccine works by inducing a mild, controlled infection that stimulates the immune system to produce antibodies and immune cells against VZV.
**Why the Correct Answer is Right**
The varicella vaccine contains a weakened form of the VZV virus, which triggers an immune response without causing the full-blown disease. This immune response helps the body recognize and fight off VZV infection in the future. The vaccine is administered as a two-dose series, with the first dose given at 12-15 months of age and the second dose at 4-6 years of age.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify the type of varicella vaccine. There are different types of varicella vaccines, including live attenuated and inactivated vaccines.
**Option B:** This option is incorrect because it implies that the varicella vaccine is a single-shot vaccine, whereas it is typically administered as a two-dose series.
**Option C:** This option is incorrect because it does not accurately describe the varicella vaccine. The vaccine is not a "killed-virus" vaccine, but rather a live, attenuated vaccine.
**Clinical Pearl / High-Yield Fact**
It's essential to note that the varicella vaccine is not a substitute for the MMR vaccine, which protects against measles, mumps, and rubella. The two vaccines are administered separately, and individuals should receive both vaccines to ensure comprehensive protection against these diseases.
**Correct Answer: B. Two-dose vaccine series.