## **Core Concept**
The global effort to eradicate poliomyelitis involves the strategic withdrawal of oral poliovirus vaccine (OPV) types to prevent vaccine-derived poliovirus cases. Poliovirus type 2 was declared eradicated in 1999, and subsequently, the use of type 2-containing OPV was targeted for removal to reduce the risk of vaccine-derived type 2 poliovirus (cVDPV2).

## **Why the Correct Answer is Right**
The global eradication campaign led to the successful elimination of wild-type poliovirus type 2. As a strategic step to completely eradicate the disease and prevent vaccine-derived cases, the use of OPV containing type 2 was stopped. This step was crucial in reducing the incidence of vaccine-derived poliovirus type 2. The specific date for the eradication of polio type 2 and the subsequent cessation of type 2 OPV use would be aligned with global health policy decisions made by organizations like the World Health Organization (WHO).

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not correspond with known global health dates related to polio eradication efforts.
- **Option B:** Similarly, this option does not align with documented milestones in the global campaign against polio.
- **Option D:** This option is not relevant to the documented history of polio type 2 eradication.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that the global eradication of polio type 2 was achieved, and the cessation of type 2 OPV use was a significant step to prevent vaccine-derived poliovirus cases. This effort underscores the complexities of vaccine-related public health strategies.

## **Correct Answer:** . 2018