I had not heard about parabiosis, the transfusion of a younger person’s blood into an older to give them more zing, but apparently it works and is being done, regularly:
https://www.naturalnews.com/2018-09-13-wealthy-elitists-literally-living-off-blood-transfusions-from-children-modern-vampires.html
“As reported by Fellowship of the Minds, members of the “healthy but wealthy” elite are paying upwards of $8,000 for 1.5 liters (34 fluid ounces) of young blood in a desperate bid to turn back the hands of time. According to the director of social work at Idaho State University, D.J. Williams -- who says he's studied people who identify as vampires for about a 10 years (hmm...a Vampireologist?)--such vampires exist in droves all around the globe.(1) He explains that they're not the cape-wearing, large-fanged folks likely conjured up thanks to horror flicks and Hollywood portrayals, but instead, real people who seek out more energy by sucking on the blood of consenting donors. In fact, he even distinguishes between the movie images and real vampires using differentiating terms such as "lifestyle" vampires and "authentic" ones. "The real vampire community seems to be a conscientious and ethical one," he says, adding that "they are successful, ordinary people." In other words, fatigued humans who suck the blood from others, creating communities that literally feed off one another's powerful needs while fearing backlash if found their secrets were discovered likely involves everyone from lawyers to presidential candidates. Who knew?”