The Biden administration is encouraging states to hold on to hundreds of thousands of soon-to-expire covid vaccine doses from Johnson & Johnson, given the possibility that additional data will show the shots are viable beyond their expiration date at month’s end. Dr. Janet Woodcock, acting commissioner of the Food and Drug Administration, told state officials during a White House call Tuesday that they could store expired doses until new data shows whether the vaccines are safe to use, according to multiple state officials. State health officials have strenuously warned vaccine administrators ...