ANCHORAGE, Alaska (AP) — Officials say the usual transportation difficulties in rural Alaska have presented unique obstacles for distribution of COVID-19 vaccines. Alaska Public Media reports that dozens of remote villages lack hospitals and road connections. And ultracold freezers required for storage of specific varieties of the vaccine are essentially nonexistent. Tribal health care providers have responded by mobilizing a massive effort delivering thousands of doses to remote areas of the state. Providers airlifted vaccine doses to villages using a fleet of chartered planes and over choppy seas on a water taxi and on sleds pulled by snowmachines.