I look at it as a race against time for the elimination of the C-Virus. The vaccines are one way to stop the C-Virus from replicating itself. See it as birth control. If a post exposure prophylaxis is created, that would be the mortal blow to the virus. The goal is to stop the C-Virus once and for all into extinction.
I believe you can still catch the virus even with the vaccine, it’s just that your symptoms will be milder. I would have to read up on that aspect.