For weeks, state officials have been blaming much of Pennsylvania’s slow COVID-19 vaccine rollout on providers unnecessarily holding back doses to make sure people got second doses when needed. In fact, they forcefully urged providers not to hold back doses, assuring them the second of the two required doses would be available when needed. Yet on Wednesday, Acting Health Secretary Alison Beam announced providers since early January have been giving out second doses of the Moderna vaccine as first doses, characterizing it as a significant mistake. More than 100,000 people could be affected, Beam said. Because of the error, Beam...