STRINGS.MISC.NOTIFICATIONS.BEING_INFECTED.MESSAGEBODY
When Duplicants come into contact with various Germs, they'll need to expend points of Immunity to resist them and remain healthy. If repeated exposes causes their Immunity to drop to 0%, they'll be unable to resist germs and will contract the next disease they encounter.
Doors with Access Permissions can be built from the BASE TAB [1] of the Build menu to block Duplicants from entering biohazardous areas while they recover their spent immunity points.