Pharmacy of the World. One in five generic pills is made here.

India makes about a fifth of the world's generic medicine by volume and a large share of the vaccines used in poorer countries. The industry grew because Indian patent law until 2005 protected the process, not the molecule, so firms competed on making the same drug cheaper. HIV treatment fell from thousands of dollars a year to tens.

• Generic does not mean weaker. A generic has to prove it puts the same active ingredient into the blood at the same rate as the original.
• Cheapness carries a duty. Regulators inspect these plants closely, because a quality failure in one factory reaches patients on several continents.