Yet most other states managed to roll out the vaccine more quickly than North Carolina, which has so far administered only about one-third of its allotment. That speed matters, as federal officials have said future distributions may be based on how quickly states are putting shots into arms. But exactly why North Carolina has fallen behind is complicated. A survey of dozens of county health departments across the state by the N.C. Watchdog Reporting Network shows a range of problems that have hampered their ability to vaccinate people in the first phase of the rollout — namely front-line health workers and the elderly. Problems include: