Other mRNA vaccines for human diseases had been under development for years before the pandemic, but none had yet reached approval. Vaccine development is norma

Other mRNA vaccines for human diseases had been under development for years before the pandemic, but none had yet reached approval. Vaccine development is normally slow, partly because nobody wants to put up the money for large human trials until they're relatively confident the vaccine will work. During the pandemic, however, governments gave financial guarantees that allowed vaccine trials to go forward right away, so SARS-CoV-2 is the first human virus with an approved mRNA vaccine. > how much more complex was it to create a vaccine for COVID-19 specifically? It's not necessarily more complex. A number of different approaches ultimately worked, including one of the oldest technologies: growing virus in eggs and then chemically inactivating it. However, mRNA vaccines worked the best, and had less side-effects than most other approaches.