What? The disease began in the 1970's? That's like... a single lifetime ago. I would expect the scope of the infection to be very very limited, like, to one country at most. There also hasn't been enough time for vampires to be established as a species, with any intriguing history, or with even any infected individuals having amassed any kind of social order, self-identification, or financial security. They'd basically be animals in the woods, struggling to survive, and it would be nearly impossible to run into another vampire to befriend them. I find that very frustrating for creating a good background for my vampire. 

Perhaps you could say that vampirism was only 'discovered' in the 70's, in this country. Maybe one vampire decided to break code and let himself and his children get discovered or something.