For the military to win a war dip shit. Not for the citizens of the colonies. It was also carried out through scrapings from an already mended host via knife, and then transferred into a new host via open cuts. The proclamation was also written with an expiration (sun set) as was many of the proclamations so as to not continue the tradition England had burdened upon the colonies with their proclaimed decrees, Or as they would have referred to as oppression.
This was not GENE THERAPY like the mRNA tech being used now. This was sharing of antibodies from a host who had recovered from pox.