Gossamer Veil

Source Potions and Poisons pg. 26
Type ingested; Addiction minor, Fortitude DC 18
Price 20 gp
Effect 1 day; +4 alchemical bonus on saving throws against disease effects
Effect after 1 day; –4 penalty on saving throws against disease effects for 7 days
Damage 1d4 Wis damage
Cultists of Ghlaunder and similar manipulators wander the streets of impoverished neighborhoods, administering this “vaccine” to prevent diseases common in squalid conditions, often with an admonition that it remains effective only as long as the recipient maintains faith in the priest's deity.