Please read the article I linked on Dhampirs, which is the "technical" term for half vampire.
Hoping you will forgive the correction: there is a series of fantasy books (recently published) that revolves around a 'Dhampir' - and that is likely the basis for the UESP wikki. Other than that, forty years ago (or ten years ago) there was not a word about the Dhampirs - the early Vampire books and films all had the transmission of the disease by bite as standard. So I suspect that article is sourced on a modern fantasy series that is itself based on the traditional Victorian-English invention of a Vampire.
Yes, the word Vampire was always thought to be the invention of a Victorian Englishman (the name Bram Stoker seems to ring a bell) who travelled around Europe and was based on the truth of Vlad the Impaler who had a habit of stringing people up on wagon wheels set on poles - I'm sure you've seen the artwork of Hieronymous Bosch.
Vlad wiped out an Ottoman/Turkish invasion of hundreds of thousands with his tens of thousands taking prisoners and putting them on the wheels all along the roads as a warning in the ancient Roman manner - and then did the same to many of his Dacian/Transilvanian peasants when they revolted in his absence. Natch the peasantry decided they did not like him too much and made up a lot of tales about his 'unnatural need for blood' - but then of course they were revolting.
Just in case you have the idea that the Ottomans were a nice eco-friendly lot please read up on Jannisaries = kidnapped children reared as elite Ottoman soldiers with no knowledge of their parents or home ... so (unless the Jannisaries are a more modern phenomenon) those peasants revolted against the man who saved them from certain death and their children from what they might have felt was worse. Byzantium and Dacia served as the bulwarks of Europe following the partition and collapse of the Roman Empire and saved the rest of Europe from even worse than the Western Europeans did to themselves.
In-game as has been said Lore is sparse - rumour as much as fact - though there is that 'book' about cross-breeding between the races - not sure if it mentions Vampires specifically?