How was a COVID-19 vaccine developed so quickly?

Scientists have been preparing for this situation for many years. About 30 years ago, a handful of scientists began exploring whether vaccines could be made more simply, and after the Ebola outbreak in 2014-2016, the Jenner Institute at the University of Oxford designed a strategy for defeating what was then an unknown virus using a “plug and play” technology. This allowed scientists to be ready to start vaccine development as soon as they got ahold of the coronavirus. That, coupled with significant funding and a high prioritization by all nations, allowed the vaccine to be developed and authorized much more quickly than one might expect. It should also be noted that at least two other pharmaceutical companies tried to make a vaccine but could not get authorized. The ones that get authorized have been through a strict, rigorous process to ensure safety and effectiveness.

Sources and more information:

https://www.health.harvard.edu/blog/why-are-mrna-vaccines-so-exciting-2020121021599

https://www.bbc.com/news/health-55041371