Kelley Mack, an actor who starred in "The Walking Dead," died due to complications from the COVID-19 vaccine. Actor Kelley Mack, who was best known for playing Addy on the TV show "The Walking Dead," died at age 33 on Aug. 2, 2025, her sister announced in an Instagram post .

Actor Kelley Mack, best known for playing Addy on "The Walking Dead," died over the weekend, her family announced. She was 33. "Such a bright, fervent light has transitioned to the beyond, where we all eventually must go," her sister Kathryn wrote on her Instagram page Tuesday.

Kelley Mack, an American TV actress who appeared in AMC’s “The Walking Dead,” “9-1-1” and “Chicago Med,” died on Aug. 2. She was 33. Her family reported in a statement that Mack died in her hometown of Cincinnati after a battle with glioma of the central nervous system. Mack graduated from Hinsdale Central High School …