Since no one really knows who the real Jack The Ripper was, and there have been countless different people, both in real life and in fiction, claiming to be him or bearing his name, I'd argue he fits the idea of an omniversal meme even better than Dracula does. Because Dracula is fictional (even if Vlad Tepes, the inspiration behind his legends, was a real person). But Jack The Ripper was not only "real", but nobody knows who he really was or how truly real was he.
Hell, even Dracula's creation was inspired by it. Bram Stoker directly used elements of the Whitechapel murders in his manuscript.
Last thread I argued that Dracula's multiple varied appearences and power across media are due to him trascending space/time/matter into the realm of pure concept. A fictional character in the real world inspired by real people, leaves such an impact in the real world that he appears in endless permutations across fictional worlds. A pervasive meme that grows stronger the more he appears. I argued that all ideas are like this, non-existing until they do, and spawn or take elements of others.
When it comes to Jack The Ripper and Jekyll/Hyde though, there's something interesting.
When the Jack The Ripper murders were first commited, people routinely referred to the killer as Mr Hyde. Jekyll & Hyde was already a very popular story, and at the time of the murders there was a popular play ongoing. The play had to be closed, and at least one person sent letters to the police asking the lead actor to be arrested under suspicion that he was the murderer.
Jack The Ripper and Edward Hyde were practically born together. The idea of a well-dressed, vicious monster laying waste to whatever pretension of nobility and respectability Victorian London still had left. Or, in a broader sense, the idea of a split personality within man, a divide between his selves, is something extremely pervasive even today, arguably the bed rock of superhero fiction.