Amber Riley, the Glee star who opened to rave reviews in her West End stage debut as Effie White in Dreamgirls, is currently out of the show, following a diagnosis of pneumonia. According to a statement by the producers, "Fortunately, Amber is now in the final stages of recovery and is expected to return to the show in the next few days."
As well as the original Effie alternate Karen Mav, the producers have also announced that they have "recently engaged Broadway star Marisha Wallace to play Effie White for certain performances. Wallace has performed the role of Effie in a recent U.S. production of Dreamgirls and has been seen on Broadway in Something Rotten!, Disney's Aladdin and on tour in The Book of Mormon." All of those titles are directed and choreographed by Casey Nicholaw, who is also responsible for this new incarnation of Dreamgirls.
The producers have further acknowledged that "several of the cast members of Dreamgirls have been ill over the holiday season" and added, "The company has been working with doctors to ensure that they all recover as quickly as possible, taking every precaution that they do not come back too quickly and become ill again."