New research shows that using smaller, fractional vaccine doses during epidemics can significantly reduce infections, especially when vaccines are scarce or distribution is limited. The study When Should Fractional-dose Vaccines be Used? by Francis de Véricourt, Professor of Management Science and academic director of the DEEP – Institute for Deep Tech Innovation at ESMT Berlin, Jérémie Gallien, and Naireet Ghosh (London Business School), provides the first analytical framework to determine when and to what extent vaccine doses should be fractionated to maximize public health benefits.