On the outskirts of Marburg, a small college town in Germany, coronavirus vaccine manufacturer BioNTech has spent five frantic months renovating one of its factories to produce mRNA. Demand for the vaccine has been so massive that the Pfizer-BioNTech partnership can’t meet it with its existing facilities--hence the race to retrofit factories that weren't initially designed to support the vaccine. Naomi Kresge reports that success would mean being able to vaccinate about 375 million more people per year, and help bring the pandemic under control.