The Mary Tyler Moore Show star, who was diagnosed with terminal brain cancer in 2013, was hospitalised in Maine after falling ill while preparing to hit the stage for the Ogunquit Playhouse's production of Nice Work If You Can Get It.
The 75 year old was released from hospital on Thursday (30Jul15), and assured fans she is on the mend, but she will not be returning to her role as Millicent Winter for the rest of the production's run.
Ogunquit executive artistic director Bradford Kenney announced that Oscar nominee Vaccaro will be assuming the part starting on Tuesday (04Aug15), until the end of the show's run on 15 August (15).
The statement reads: "Valerie is feeling great right now and we want her to continue to rest and to enjoy her family. After discussing with them, we decided that we wanted to relieve her of any pressure of having to return to the show, which only runs for two more weeks.
"With Valerie's blessing, the Ogunquit Playhouse is thrilled to announce that Brenda Vaccaro, star of film, television and stage, has arrived in Ogunquit to take over the role of Millicent Winter."
Nice Work If You Can Get It also stars Emmy winner Sally Struthers.