Back story for my Novel

For the vampires to survive they had to use the nousfuratues to cleanse the human blood lines every 55 years. Because there is only one blood line that is toxic to all vampires except for the nousfuratues. That is how it has been since the beginning of recorded time. Yet during the mid 18th century all of Eastern Europe was in a panic about vampires and began to hunt and mass murder them. Freya's family split apart and fled to the new world. What they did not know was that the humans in the new world were onto the presence of vampires. It was them who came to create a vaccine that will rid them of any and all vampires here in the USA. It would just take time to create the right formula. After decades of research and experiments the timing became perfect. In 1973 there was a Swine Flu Epidemic, that is when the creation was introduced as a vaccine. The creation is known as VGR (Vampire Growth Regulator) if a vampire attempted to turn a person the human would die, if a vampire fed off of a human the vampire would die.
Freya is now a successful photographer and art dealer. She has an underling by the name of Rachel. She has been with Freya for 15 years. Her job is to run Freya's daily tasks. Such as running errands, running the art galleries, setting appointments for photo shoots, protect her employers lair from preying eyes, and her most important job is to insure Freya's secret remains a secret.
Freya has a "Sister" and a "Brother" each one of them have sired. Her "Brother" has sired 4 where as her "Sister" has sired only 3. Freya has sired 2 and they have sired as well. Her family was once in the hundreds but now, today they barley reach 35 strong.