‘The Case Study of Vanitas’ (aka Vanitas no Carte) released a special episode that recaps events of the first 12 episodes of season 1. This special episode (also known as “Episode 12.5”) is titled “En route pour le Gévaudan”. In addition to the synopsis, this episode provides some information about the upcoming episode.
The 2nd season of the anime premiered on January 15, 2022 at 24:00 JST.
“During an airship ride to Paris, the vampire Noé Archiviste meets Vanitas, a human claiming to be a doctor for vampires, curing them of the malnomen, which cause vampires to behave predatorily against their will. The book with which he heals, The Book of Vanitas, is connected to the original Vanitas, the Vampire of the Blue Moon, hated by the Vampires of the Red Moon who form traditional vampire society. Noé and Vanitas join forces to heal vampires, but there lurks a threat of some unknown force named Charlatan, which may be responsible for corrupting the sick vampires.”