## **Core Concept**
The Rubella vaccine, often administered as part of the Measles, Mumps, and Rubella (MMR) vaccine, is crucial for preventing rubella (German measles), a contagious viral infection that can cause severe birth defects if a pregnant woman contracts it. The vaccine is recommended to be given to children to ensure immunity before they reach childbearing age.

## **Why the Correct Answer is Right**
The correct answer, . (at 15-18 months or 4-6 years), is right because the Rubella vaccine is typically administered to children in two doses: the first dose at 12-15 months of age and the second dose at 4-6 years of age. This schedule ensures that children develop immunity against rubella early in life and have a booster to maintain long-term immunity. This is particularly important for females to prevent congenital rubella syndrome in case of pregnancy.

## **Why Each Wrong Option is Incorrect**
- **Option A:** (at birth) is incorrect because the Rubella vaccine is not given at birth. Vaccines administered at birth include BCG (Bacillus Calmette-Guérin) for tuberculosis and Hepatitis B.
- **Option B:** (at 6-9 months) is incorrect because, although some vaccines are given at this age (like the first dose of the Hepatitis B series, DPT, and Hib), the Rubella vaccine is typically given later.
- **Option D:** (at 10-14 years) is incorrect because, by this age, the individual should already have received the two-dose series of the MMR vaccine, which includes Rubella.

## **Clinical Pearl / High-Yield Fact**
A crucial point to remember is that the Rubella vaccine is contraindicated in pregnancy due to the theoretical risk of transmission of the vaccine virus to the fetus. Therefore, it's essential to ensure that women of childbearing age are immune to rubella before pregnancy. This is often checked through serological testing.

## **Correct Answer:** . 15-18 months and 4-6 years