Shouldn't YG have developed immunity to LMS's Bing Pak Silver Needles?

[Ken Cheng]

"What doesn't kill me makes me stronger." This popular aphorism is literal when it comes to how the immune system works. If an antigen enters one's body and doesn't succeed in killing one, then one's body develops antibodies that will fight off those antigens in the future, making one immune to that particular antigen.

That being the case, shouldn't Yeung Gor have become immune to Lee Mok Sau's Bing Pak Silver Needles at some point before her death? By my count, there are at least three (maybe even four) occasions that Yeung Gor was stricken by the Bing Pak Silver Needles, and he survived each time.

1. When he was a kid, playing around with a Bing Pak Silver Needle that Lee Mok Sau had meant to use against East Heretic Wong Yerk See. West Poison Au Yeung Fung saved Yeung Gor that time.

2. This might be TVB only, but he was possibly stricken a second time by this kind of needle while trying to rescue Luk Mo Seung from Lee Mok Sau. He purged it using the techniques that Au Yeung Fung taught him.

3. Exposed to the poison a third time after saving the lives of the Mo Brothers, sucking the poison out of their bodies. He survived this one because the Passion Flower Poison and the Bing Pak Silver Needle Poison counteracted each other.

4. Stricken by errant needles by Gwok Fu. Little Dragon Girl gave him the antidote, which they had taken from Lee Mok Sau.

That's four separate exposures to (and four separate recoveries from) the same kind of poison (is that a record in wuxia?). If he survived all four, he must have had immunity to this kind of poison after the fourth and final exposure.

When you think about it, it makes no sense for Yeung Gor to be vulnerable to any kind of poison considering that the master of all poisons (Au Yeung Fung) taught him how to purge poison, but Yeung Gor spent a huge chunk of ROCH hampered by Passion Flower Poison and assorted other poisons (not to the extent of Ling Wu Chung, however).

[Banh Mi]

People immunise themselves that way with very small doses over many attempts and a long time. 4 times might be feasible with Wuxia logic, but I doubt it's that easy in reality.

[tape]

I saw an episode of Spike Lee's "Superhumans", and one of the subjects was someone who became partially immune to a certain snake poison after repeatedly taking small doses of it. This took about 15 years and hundreds of doses...much more than Yang Guo's 4. I guess snake poison doesn't quite work like a vaccination.

[Ken Cheng]

I don't know how much of his poison-purging skill Au Yeung Fung taught to Yeung Gor, but if it was anything near complete, then Yeung Gor should have had no vulnerability to poison throughout ROCH (of course, that would send a number of plot lines askew).

[tape]

It wasn't anything near complete. He taught him to reverse his bloodflow and drip the poison out of his fingertips, and that was about it. Besides that brief tutorial, I don't think Yang Guo learned anything more. Despite OYF's mastery over poison, I really doubt he can teach a 7 year old boy to be able to purge all poisons within an hour.

The fact that he was able to remove the Soul Freezing needle poison is pretty unbelievable in itself, and the only explanation I can think of is that he touched the needles rather than having them thrown into him, or else he wouldn't have such an easy time removing it.