[Kirk had already been publicly outed as a vampire during the Aphaia mission. While he certainly isn't happy about it and isn't going to publicly shout it out every time it comes up, he's accepted that this is the kind of conversation he has to have multiple times. It's still not great though.

Jayce's question is one that Kirk himself has contemplated over many times. An uncomfortable silence hangs in the air as he thinks about how to reply]

We only recently decided to minimize killing. For many years after my transformation, killing criminals was my way of making the best out of something terrible. Animal blood can only go so far and even artificial plasma is different from human.