I... don't believe I ever said that, actually. If I did, it was most certainly a typo. As far as I recall, the closest I've ever said regarding that is that sometimes Wage Slaves were re-conditioned in Sundown, but I don't believe I ever said they became immune to the virus. The purposes of this reconditioning are left intentionally vague for future events, but I can assure you Wage Slaves by no means develop an immunity simply by not drinking the water. The moment they start drinking again, they'll be indoctrinated as they were before.

EDIT: Also, closed means [i]we are not recruiting anymore[/i], not that the roleplay is finished. TSTS is still alive and going.