This is a power/school principally used by Serpent Men as their second channel (cf Avatars of Yig-Tsathoggua). It might also be used (with some modification) as an Adept school.

Vaccinomancy:

This is the serpentine, alchemical power to convert poisons and diseases into cures (and vice versa) through the medium of one’s body and blood. Before the widespread use of Vaccines, it was known as Inoculomagy or Homeurgy. It gave rise to the “school” of Homeopathy among humans, but humans have been forced to greatly dilute their preparations due to the fact that, by and large, it doesn’t work for them. A sufficiently obsessed human might be able to re-make a school out of it.

Avatars of Yig possessing this power grow poison sacs within their throats, giving them a perpetual “puffy glands” look, and ducts within canine teeth through which the substances can be injected with a bite, or drained for later administration by other methods (within a day – it doesn’t keep).

Limitations:
The power and rarity of the resulting substance is directly proportional to the power and rarity of the originally absorbed substance.

Apart from the conversion, which neutralizes the original substance, the power grants no immunity to the ingested substance, so failing a roll means you suffer the consequences of the poison/disease. No, you can’t try again later. Shut up and die.

The Avatar’s poison sacs can only hold enough of the created substance for one dose for one person, so “charges” cannot be accumulated – repeating the application of the power flushes out the old substance. In addition, once removed from the avatar’s body, the transmuted substance will only keep for a day before “reverting” back to its original.

You can administer the resulting substance to yourself.

The substance produced cannot be duplicated scientifically. If analysed, it appears identical to the original substance (so, for example, if an Avatar was to claim to have a cure for HIV, an investigation would “prove” that all he was doing was injecting his patients with more HIV).

“Absorb” below is used as a catch-all for inject, drink, snort, take up the arse, etc

Some examples:
Get infected with the flu <=> create a vaccine against that strain of flu, or similar disease (common cold, etc).

Drink a bottle of methylated spirits <=> create an instant sober-up/detox potion (dipsomancers hate this one).

Create or absorb a potion of longevity, cutting edge experimental anti-biotic, etc <=> absorb or create a fatal degenerative disease e.g. HIV/AIDS, Leprosy.

Create or absorb a potion of eternal life OR eternal youth <=> absorb or create a one-of-a-kind disease or poison capable of destroying human life on earth e.g. a top of the line, genetically engineered, military bioweapon.