There's no inoculation for this plague.
http://www.nintendoworldreport.com/news/41121/shovel-knight-plague-of-shadows-release-dated
Yacht Club Games has announced the release date for the first Shovel Knight expansion.
Plague of Shadows will release on September 17, a week from tomorrow in all regions where the base game is available, for both 3DS and Wii U. The expansion will come as a free update to all Shovel Knight owners.
The Plague of Shadows expansion is a total conversion of Shovel Knight, featuring Plague Knight as a playable character with a unique double jump ability.
