Vampire-Human relationships in True Blood are set up as a metaphor for same-sex relationships. They are hated by the right wing Christians, legally persecuted, and at one point they sneak in a reference to vampire-human marriages being legalized in Vermont. However, the relationship dynamics are built on difference and the societal oppression is based on one person who is hated for being "unnatural" and other person who is hated for loving them. There's even a population of humans called 'fangbangers' that exoticize and seek out vampires as the ultimate lovers. That's a lot more like trans-cis relationships. Watch this video I put together and judge for yourself
While there's a lot of gay, lesbian, and bisexual characters on TV, we don't get a lot of trans representation. When we do, it's often been less than ideal representation. Slowly trans characters have moved from crime show psychos to crime show victims to hospital show victims and finally for sensationalism on drama and reality tv shows -- and that's a major improvement! But as far as an ongoing representation of a major trans character in a healthy, supportive, and affirming relationship, well I can't find anything like that. But at least when I watch True Blood I can pretend. It fits so well I have to wonder if it was the intention.