WHO declared that smallpox has been eradicated in
**Core Concept**
The question is based on the historical achievement of global **smallpox eradication**, a significant milestone in public health. This was made possible through a concerted global vaccination effort led by the **World Health Organization (WHO)**. The eradication of smallpox is a testament to the power of **vaccination** in preventing infectious diseases.
**Why the Correct Answer is Right**
The correct answer is related to the year when the WHO officially declared that smallpox had been eradicated worldwide. This declaration was made after no new cases of smallpox were reported for an extended period, confirming the success of the global eradication campaign. The **global vaccination campaign** against smallpox, which started in 1959, led to the eventual eradication of the disease.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not correspond with the historical record of when smallpox was declared eradicated.
**Option B:** Similarly, this option is also incorrect as it does not match the correct year of the declaration.
**Option C:** This option is incorrect for the same reason, not aligning with the actual year the WHO made the declaration.
**Option D:** This option is also incorrect as it is not the year the WHO declared smallpox eradicated.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that smallpox is the first and, to date, the only human disease that has been completely eradicated from the planet, thanks to **vaccination efforts**. This highlights the potential for vaccines to control and eliminate infectious diseases.
**Correct Answer:** Correct Answer: 1980. The year smallpox was declared eradicated by the WHO.