From the polio vaccine to mRNA vaccines, this exploration of scientific inquiry celebrates the greatest developments in vaccine science. Get to know the scientists responsible for these breakthroughs, and explore science in action.

Vaccine salvation -- The world's first vaccine -- Discovering attenuated vaccines -- Modern mix defends kids -- Combined vaccines save more lives -- Needle-free vaccination arrives -- Scientist spotlight -- Mock virus vaccine prevents cancer -- Mysterious antibody link? -- COVID-19 vaccine: global relief -- Timeline -- Glossary.