People fear what they don't understand. This has been said in many ways by many people. History has shown us a thousand examples of mythologies and superstitions that were created to explain the unknown. The fear of death and disease is inherent in humanity. From these fears arose the legends of the vampire.
Tales of monsters that attacked people and drank their blood have been around for thousands of years in cultures around the world. However, it wasn't until the 1600s that the modern construct of the vampire began to take shape. This modern creation borrowed pieces of other legends: the Greek empusae, the Norse draugr, and many more. These would mix with the Slavic upir to become something akin to what we think of when we hear "vampire" today.
In the 1700s, Europe had a "Vampire Epidemic" where people throughout the continent believed vampires were very real and causing illnesses. This led to vampires turning into characters in popular culture through the remainder of the century and into the 1800s. Many of the characteristics of the vampire were solidified at this time: they were undead, drank blood, had fangs, they were sophisticated, they had an aversion to sunlight, and the stories had undertones of eroticism.
This culminated in Bram Stoker's "Dracula" (1897). Much like people had done for the centuries before him, Stoker borrowed from previous vampire books and the history of Vlad Tepes to create the modern myth. But disease was still part of the story. The characters were infected with vampirism which reflected the true diseases of the time.
Multiple diseases were running rampant in 18th and 19th century Europe. Many of the symptoms seen with these diseases, especially rabies, coincide with the symptoms of the vampire: an aversion to light and strong odors, disturbance of sleep patterns, hypersexuality, and biting others hard enough to draw blood... and spread the disease. Two of the main carriers of rabies were bats and wolves. It was no accident that these animals are associated with vampires.
This was also the time that modern medicine started. Corpses were sometimes disinterred only to find they had not decayed, looked full, and their nails and hair had "grown." We now know the science behind this. Other times, fingernail marks were found on the insides of coffins and the body had been moved. Sadly, also due to the infancy of modern medicine, some people were buried alive.
With the stories of vampires so ingrained in Western culture, it should surprise no one that Hollywood began to tell stories of vampires and two of the most popular films, "Nosferatu" (1922) and "Dracula" (1931) were based on Bram Stoker's novel. Since then, vampires have remained popular albeit with some waxing and waning of their popularity through the decades.
Just some examples of popular portrayals of vampires in Hollywood include Christoper Lee's run as Dracula in ten films starting in 1958. ABC ran the popular "Dark Shadows" soap opera from 1966-1971. More recently, 1992 saw the release of "Bram Stoker's Dracula" and "Buffy the Vampire Slayer" (the latter was made into a popular television show with its own spin-off). In 2008, the saga of "True Blood" on HBO, and the "Twilight" films began. More recently, "What We Do in the Shadows" started as a film in 2014 and continued with a series that started in 2019 with its final season airing now.
Vampires have captivated audiences for well over a century, and they show no signs of slowing down. While contemporary audiences are very different from those who listened to tales in previous centuries, deep-down humanity is still the same: we still have fears of death and disease, and we are still seduced by the charisma and allure of the vampire.