Since 2020, very many people across the globe have been vaccinated against Covid-19, but the exact structure of this vaccine has remained largely unknown until now. Prof. Dr. Tobias Unruh from the Chair of Crystallography at FAU and his team are now taking a closer look. The results of their complex analyses differ at times considerably from previous expectations. Active substances and pharmaceutical excipients incorporated in these mRNA vaccines appear not to be solid, as was previously suspected, but instead consist of numerous liquid nano droplets.