Sen. Dianne Feinstein, the 89-year-old California Democrat who announced last month she would retire rather than run again next year, has been hospitalized for treatment of shingles.

“I was diagnosed over the February recess with a case of shingles,” Feinstein said in a statement. “I have been hospitalized and am receiving treatment in San Francisco and expect to make a full recovery. I hope to return to the Senate later this month.”

Feinstein is the second Democrat in the chamber that the party controls — by a 51-49 margin — to be hospitalized. Pennsylvania Sen. John Fetterman is being treated for depression.

Feinstein’s absence, so far, has not impeded Senate Democrats’ slow-moving process to confirm President Joe Biden’s judicial and executive nominees. After Democratic Sen. Jeff Merkley flew home to Oregon on Monday following the death of his mother, Vice President Kamala Harris has been called in to break several ties on nomination votes.

But Feinstein’s illness could hinder the efforts of some House Democrats to convince enough of their Senate colleagues to vote down a House-passed measure that would block a District of Columbia Council-passed bill that revises the city’s criminal code.

Biden told Senate Democrats during a luncheon meeting in the Capitol he would not veto it, should they pass it. A floor vote would need only a simple majority and could come as soon as next week.