“Before the introduction of the measles vaccine in 1963, the country saw hundreds of thousands of measles infections each year. Within a decade of the vaccine’s roll-out, infections in the United States plummeted from about 450,000 a year to fewer than 50,000 (see ‘Measles cases in the United States’). …

The world is teetering on the edge of eradicating polio, thanks to a global vaccination campaign that has eliminated the virus in every country except Afghanistan and Pakistan. …

In total, childhood vaccinations have saved about 154 million lives over the past 50 years.”

From Nature.