A quick look at the vaccine trials process:

https://en.wikipedia.org/wiki/Vaccine_trial

Additional links gathered from the above:

https://link.springer.com/book/10.1007%2F978-0-387-68636-3

https://www.sciencedirect.com/science/article/pii/S0264410X04009715?via%3Dihub (warning: Elsevier)

https://books.google.com/books?id=D0QW31ivHcwC&pgis=1

https://nu.federati.net/url/275239