The Saal Sou was developed by theOtâmovi Wiy Jael (Silver Moon Sect) for use by members of the Poku Saeruo Degonjo in 739 CY YE 21. It is for use protecting the Poku'vonai from known viruses by inoculation. It is updated periodically to ensure currency. This practice started after 537 CY The Weakening which decimated the clan.

Saal Sou is only released to medically trained personnel, and is dispensed in auto-injector ampules. One ampule is sufficient for any adult member. Typical reaction to the inoculation is feeling unwell for a day or two.