Fabian's execution was the flame that started it all. The vampires soon began to do more research on the exchange of blood for a new one.
Not everyone knew about them, not that it was a common thing either, so they were expected to research the procedure. Everyone tried to talk to the elders they know or the most knowledgeable vampires. So they would find out about the procedure, how it is performed and its likelihood of success.
But the chance of success although low was not nil, not to mention there was Elder Carl who went through the procedure and did perfectly. That made many feel motivated to accept the offer and many quickly went for the operation.
In one day Valery could do 50 or more operations by herself, and only she could do the operations because if she gave the ice tools to other vampires they could not feed on the strength of her physique and would not freeze and stop the regeneration of the operated vampires.