It was a pleasure to attend the 15th International SLS Days hosted at Twincore GmbH. Serum Life Science Europe GmbH (SLS Europe) organizes this symposium to provide an excellent opportunity for fruitful exchange of ideas and networking between various stakeholders. SLS Days are not only for experts in the pharmaceutical and vaccine industries, but also for the academic research community, biotech companies, regulatory authorities, IP/legal consultancies, and venture capital firms.