Zero dose of Polio vaccine in which is given:
**Core Concept**
The zero dose of Polio vaccine is an essential component of the oral poliovirus vaccine (OPV) schedule, administered to newborns to provide immediate protection against poliovirus infection.
**Why the Correct Answer is Right**
The zero dose of OPV is given to newborns within the first few days of life to ensure early immunity against poliovirus. This dose is crucial in preventing polio transmission, especially in areas with high polio prevalence. The World Health Organization (WHO) recommends administering the zero dose at birth to ensure maximum protection against poliovirus.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because the zero dose is not a booster dose, but rather the first dose of OPV administered to newborns.
**Option B:** Incorrect because the zero dose is not a dose given to adults, but rather to infants to prevent polio transmission.
**Option C:** Incorrect because the zero dose is not a dose given to children who have already received the full OPV schedule.
**Clinical Pearl / High-Yield Fact**
The zero dose of OPV is a critical component of polio eradication efforts, and its administration at birth is essential in preventing polio transmission, especially in high-risk areas.
**Correct Answer:** D.