In Harry Potter, is there a cure to werewolf bites?

Question

In Fantastic Beasts (the textbook) we find this:

The werewolf is found worldwide, though it is believed to have originated in northern Europe. Humans turn into werewolves only when bitten. There is no known cure, though recent developments in potion-making have to a great extent alleviated the worst symptoms. Once a month, at the full moon, the otherwise sane and normal wizard or Muggle afflicted transforms into a murderous beast. Almost uniquely among fantastic creatures, the werewolf actively seeks humans in preference to any other kind of prey.

However, in Prisoner of Azkaban, Lupin says:

I as a very small boy when I received the bite. My parents tried everything, but in those days there was no cure.

Although that could possibly be referring to the Potion, which is referenced in the next sentence.

However, in Sorcerer's Stone, Harry and Hermione learn about cures for werewolf bites:

The next morning in Defense Against the Dark Arts, while copying down different ways of treating werewolf bites, Harry and Ron were still discussing what they'd do with a Sorcerer's Stone if they had one.

Which implies that there is a not only a treatment, but multiple treatments! Or is that referring to the potion as well?

Answer 1

There is no cure for someone who's already become a werewolf.

This passage states that there's no way to cure a werewolf, not necessarily that there's no way to cure a werewolf bite.

Humans turn into werewolves only when bitten. There is no known cure, though recent developments in potion-making have to a great extent alleviated the worst symptoms.
_{^{Fantastic Beasts and Where to Find Them}}

There's no cure for werewolf bites, but there are treatments.

Bill Weasley was bitten by a werewolf (not on a full moon), and he gets his bites treated. Madam Pomfrey says there's no cure, but there are treatments that she uses on him, despite there not being a complete cure. The students could be copying down these methods in their Defense Against the Dark Arts class. They're copying down ways to treat werewolf bites, which is different than curing them, and the existence of treatments don't contradict the fact that there is no known cure.

“Harry looked over Hermione’s shoulder and saw an unrecognisable face lying on Bill’s pillow, so badly slashed and ripped that he looked grotesque. Madam Pomfrey was dabbing at his wounds with some harsh-smelling green ointment. Harry remembered how Snape had mended Malfoy’s Sectumsempra wounds so easily with his wand.

‘Can’t you fix them with a charm or something?’ he asked the matron.

‘No charm will work on these,’ said Madam Pomfrey. ‘I’ve tried everything I know, but there is no cure for werewolf bites.”
_{^{- Harry Potter and the Half-Blood Prince, Chapter 29 (The Phoenix Lament)}}

When Lupin refers to a "cure", he means the Wolfsbane Potion.

Lupin saying that "in those days there was no cure" refers to that he had to transform into a murderous creature every month, instead of being able to transform but keep his mind so he's not a danger to himself or others. That his parents tried everything probably referred to them attempting to make his transformations easier on him and less dangerous, which there would be no way of doing before Wolfsbane Potion.

Answer 2

The phrasing of the first and second quotes reference two different types of cures. The first being that no cure exists for those who are werewolves to be cured of lycanthropy. The second being that there was no cure, at the time, for bites which lead to lycanthropy, but since then cures have been made available. This is affirmed by the third quote, which says there are ways of treating "bites", but doesn't say anything about treating lycanthropy itself.

It's somewhat comparable to rabies. There is a cure for it if treated soon enough that allows for full recovery. After a certain point however, it is no longer treatable, and there is no cure.