If messenger-RNA vaccines are the breakout medicine of the pandemic, then the tiny lipid spheres that bring them into people’s cells are the unsung heroes.

The world desperately needs more of both.

Consider BioNTech SE, which until a year ago purchased only a few grams at a time of lipids to support a drug-development program that most people thought was years away from becoming mainstream. Now it’s tapping big German chemical companies like Merck KGaA and Evonik Industries AG to vastly scale up production of the materials, a crucial step if it and partner Pfizer Inc. are to make good on plans to ship 2 billion doses of their COVID-19 vaccine this year.