The COVID-19 pathogen led to a fast expanding pandemic because it proved lethal in certain populations but could be transmitted by persons who appeared healthy. As a result, researchers came under unprecedented time pressure to develop a vaccine. This case study focuses on the first COVID-19 vaccine, which was approved for use in humans, known as Comirnaty, the BioNTech-Pfizer COVID-19 vaccine or Vaccine BNT162b2. With the benefit of hindsight, we show how close collaboration with regulators and trust-based decisions meant that the race for a COVID-19 vaccine was won without purposefully infecting healthy participants with an infectious agent that can cause severe illness or death and for which no rescue therapy had existed.