Second-dose confusion lingers over first two days of United Center vaccinations, but changes expected to come Thursday

The federally run United Center mass vaccination site opened Tuesday after initially being heralded as a source for a much-needed influx of coronavirus inoculations for all eligible Illinois residents under phase 1b. Shifting guidelines, however, have dogged its rollout. The original plan was to allow Illinois residents 65 and older to register last week until 4 p.m. Sunday, when slots would open up to any Illinoisan with certain health conditions or a front-line essential service job. A last-minute change to restrict sign-ups to only Chicagoans and, later, suburban Cook County residents, threw off some residents.