Voigt was suffering from a cough, according to the Boston Herald.
Elizabeth Byrne stepped into the role of Senta at the last minute and drew decent reviews. Herald critic T.J. Medreck wrote that she "sang with bright tone and firmly conveyed her character's obsessive resolve"; the Boston Globe's Richard Dyer praised her "solid, plucky, professional performance." Both critics noted that she struggled a bit with high notes.
A spokesperson for the BSO said that it was not yet clear whether Voigt would be able to return on March 15 for the BSO's final Dutchman.
The BSO's performances are conducted by music director James Levine, and also feature Juha Uusitalo as the Dutchman.