McClellan provided an additional voice to explain what has been detailed by many residents as "confusing".
"The real challenges have been getting that last mile, or the last inch, from the vaccines being distributed out to health care facilities, or are going to be used in nursing homes, getting from there into people's arms," said McClellan. "That's not a matter of logistics and distribution at the national level."
Recently, President Donald Trump signed legislation attached to the coronavirus relief bill that would provide $8 billion dollars to assist in vaccination efforts.
However, McClellan intended to reference hiccups at the state and local level in how the vaccine is being distributed.
"It's a matter of what's the capacity for these health care organizations to set up vaccination programs?" McClellan questioned. "Many of these hospitals are very hard-hit right now. How much willingness is there on the part of the affected staff or residents to take the vaccine? There's still a significant amount of skepticism among, particularly, some subgroups in the population."
McClellan said some healthcare personnel included in Phase 1A are also skeptical.
"These concerns, unfortunately, are not new," he said. "If you look at surveys of the American public ... people in more rural areas...people from racial and ethnic minority backgrounds, there is more skepticism out there. Some of that is long-term skepticism."
North Carolina Health and Human Services Secretary Dr. Mandy Cohen told ABC11 in a one-on-one interview Tuesday that some areas of the state are "struggling".
McClellan told reporters a somewhat similar tone Wednesday.
"Add in all of those local logistical details, for people and health care organizations that are very busy, and you can see why it's been a bit of a challenge," said McClellan.
Tuesday, Governor Roy Cooper issued a directive for the North Carolina National Guard to mobilize to assist with logistics and distributing the vaccine.
"One of the big restraints is just bandwidth," said McClellan. "Hospitals just don't have a lot of staff they can devote to expansive vaccination programs. So the more we can augment them, the better."
The former FDA and Centers for Medicare and Medicaid Services official said the entire process will improve.
"The Biden administration has already identified dealing with COVID generally, and increasing vaccinations in particular, as among the highest priorities. They've set a goal of a million vaccinations per day for the first hundred days of the administration. We are not there yet but we are headed in that direction. We ought to be able to get there. We ought to be able to get well past 1 million doses per day."