UPS package handlers Jesirae Elzey and Demeatres Ralston unload boxes of Moderna’s COVID-19 vaccine as it arrives at UPS Worldport, in Louisville, Kentucky, December 20, 2020.Michael Clevenger | Pool | ReutersCoronavirus vaccine distribution has been slower than U.S. officials hoped as the number of immunizations remains far below the U.S. government’s goal of 20 million by the end of the year, federal health officials said Wednesday.Just over 1 million people in the U.S. have received their first dose of a coronavirus vaccine as of Wednesday morning, according to the Centers for Disease Control and Prevention. That’s roughly 19 million doses shy of earlier projections for December and leaves public officials less than two weeks — about 8 days — to try to close that gap. “Exactly how fast the ramp-up of immunizations, shots in arms, is slower than we thought it would be,” President Donald Trump’s coronavirus vaccine czar, Dr. Moncef Slaoui, told reporters during a press briefing Wednesday afternoon.U.S. officials said they are still working out some kinks in the distribution system after some deliveries of doses went to the wrong destinations and others went out on the wrong day.Army Gen. Gustave Perna, who oversees logistics for Operation Warp Speed, said the U.S. government has done a “good job so far” of distributing millions of Covid vaccine doses from Pfizer and Moderna to states, territories and major cities across the nation. But he added U.S. officials are still “learning,” with the distribution process getting “better” and “stronger” each day.”We have had a handful of packages that we tried to deliver that were not destined for the right place, but we captured them before they were dropped off and we rerouted them to the right place,” Perna told reporters during a press briefing Wednesday afternoon. “And we had a couple of … shipments that did not go out on the right day.”This is a developing story. Please check back for updates.