The ongoing COVID-19 pandemic creates an unprecedented burden worldwide. Vaccine-induced immunity is the only promising solution. There is continued need for phase 2 & 3 vaccine trials to reach long-term, large-scale immunity of the entire European population. VACCELERATE will be the pan-European backbone accelerating phase 2 & 3 COVID-19 vaccine trials. The overall objective of VACCELERATE is to connect all European stakeholders involved in vaccine development to provide a pan-European platform for clinical trial design and conduct. VACCELERATE constitutes the rapid response single entry-point to stakeholders from public health authorities to vaccine developers, to address respective needs and kick-start specifically phase 2 & 3 vaccine trials. VACCELERATE conducts capacity mapping of clinical trial and laboratory sites to identify suitable sites for individual phase 2 & 3 vaccine trials. Capacity building via training will increase quality in sites across Europe. Volunteer registries facilitate patient recruitment. Access to laboratory sites and a standardised set of assays essential for clinical phase 2 & 3 trials is provided. A harmonised European approach to vaccine trials is enabled by aligning educational standards, coordination of laboratory support and providing standardised assays and trial protocols. Harmonised data collection, open data sharing and pooling of data for stronger analysis enables data standardisation. VACCELERATE offers solutions for characteristic vaccine development issues during pandemics by closing gaps in public health knowledge and improving knowledge transfer. VACCELERATE amalgamates the vast but scattered expertise across Europe into one network to deliver strategic scientific leadership and guidance on vaccine trials in Europe. Beyond the COVID-19 pandemic, it will be an established pandemic preparedness network, ready to face emerging future pandemics, as well as a pivot in Europe?s capacity to develop vaccines.