Before the polio eradication drive began, 1000 children/day were paralyzed by polio, according to the World Health Organization. Paralysis kills about 5-10% of patients by affecting muscles controlling breathing. Thus, eradication would annually save about 20,000-40,000 lives, which for a remaining life expectancy of about 50 years would be 1-2 million life-years. Eradication would also annually prevent paralysis of the remainder of approximately 300,000, thus affecting them to an extent equivalent to--let's say--4 years of their lives, or 1.2 million life-years. That would give a total of about 2.7 million life-years per year. If we arbitrarily consider the effect on one generation of about 25 years, the total would be 67 million life years.
Human News aims to devote 1 character to each 40,000 life-years, or 1000 average lives. Thus, this story has about 67 million / 40,000 = 1700 characters.