Colbert announced last week that his appendix had ruptured after a break for Thanksgiving.
The late-night host tweeted that he's 'grateful to be vaxxed and boosted.'
Joe Biden picked Harris as his running mate on Tuesday.
Will Ferrell Makes Surprise Appearance as 'Anchorman' Ron Burgundy on Late-Night TV
The 'Santa Clarita Diet' star says she has no regrets about the stunt that went down in 1995, saying, 'You only have one life!'
The 46-year-old star was to appear on the CBS show to promote his upcoming Netflix projects.
She continued substitute teaching after the 2001 hit was released.