1Before vaccines existed, terrifying diseases such as smallpox killed millions of people around the world every single year.
2The first vaccine was developed more than two hundred years ago by a country doctor.
3He noticed that milkmaids who had caught cowpox rarely became sick with the far deadlier smallpox disease.
4This simple observation led to a method of protecting people before they ever fell ill.
5A vaccine trains the human body to recognize a dangerous germ without causing the actual disease itself.
6When enough people are vaccinated, a disease can no longer spread easily through a community.
7Thanks to a worldwide vaccination campaign, smallpox was completely wiped out by the year nineteen eighty.
8Today, vaccines protect children against numerous serious illnesses that once caused great fear in every family.
9Some people still doubt vaccines, but the scientific evidence for their safety and effectiveness is now overwhelming.
10The story of vaccination shows how patient scientific observation can completely transform the health of all humanity.