A global immunization program has eliminated smallpox ​ — the lethal disease that claimed more lives than all the wars of the 20th century combined — ​ and a similar campaign has almost eradicated polio.
अशाच प्रकारच्या मोहीमेमुळे पोलिओ या रोगाचे देखील जवळजवळ संपूर्ण निर्मूलन झाले आहे.