EAST RUTHERFORD, N.J. (NewsNation Now) — More COVID-19 vaccination sites around the country are canceling appointments because of vaccine shortages. Even in areas where shots are available, confusion often reigns over who qualifies to get one.

Officials across the country are promising supply-chain improvements, even as mass-vaccination sites sit idle, waiting for shipments to arrive.

New Jersey Gov. Phil Murphy toured a vaccination center in Hudson County Tuesday, watching as Garden State residents got their shots.

One grateful recipient told NewsNation affiliate WPIX, “I just hope that they can get more vaccines out for everybody.”

So does Gov. Murphy. His state just launched a new vaccination information hotline (1-855-568-0545) that was immediately overwhelmed by the volume of calls. Murphy promises things will improve.

“17 thousand calls in hour number one?” he said.  “And how many by noon— 58 thousand, did you say?”

On the other side of the country, as it faces widespread criticism for its slow vaccine rollout, California is revamping its delivery system mid-stride by centralizing its hodgepodge of county systems and streamlining appointment sign-up, notification, and eligibility for its 40 million residents. One prominent hospital in the Bay Area is being investigated by the county after letting teachers cut in line, appearing to blame the decision on widespread confusion.

The setup inherited from the Trump administration has been marked by miscommunication and unexplained bottlenecks, with shortages reported in some places even as vaccine doses remain on the shelf.

Florida Gov. Ron DeSantis said his state can’t meet growing demand from residents partly because an increase in vaccine promised by the government hasn’t materialized.

“We are at the mercy of what the federal government sends us, and right now we are able to go through it quicker than what we are receiving,” he said.

White House press secretary Jen Psaki responded by saying that Florida has administered only about half of the vaccines it has been given.

Georgia Gov. Brian Kemp said Tuesday he doesn’t expect the state’s allotment of vaccines to increase in the coming weeks, which will limit progress in vaccinating those now eligible, including people over 65 and first responders. Rhode Island officials, meanwhile, said late last week that they can’t even expand eligibility to those over 65 at current allocations from the government, despite complaints from advocates for the elderly.

As of Tuesday morning, the CDC reported that just over half of the 41 million doses distributed to states have been put in people’s arms. That is well short the hundreds of millions of doses that experts say will need to be administered to achieve herd immunity and conquer the outbreak.

The U.S. ranks fifth in the world in the number of doses administered relative to the country’s population, behind No. 1 Israel, United Arab Emirates, Britain and Bahrain, according to the University of Oxford.

The reason more of the available shots in the U.S. haven’t been dispensed isn’t entirely clear. Some state officials have complained of a lag between when they report their numbers to the government and when the figures are posted on the CDC website.

And while some vaccination sites have canceled appointments for first-dose shots, many are believed to be holding large quantities of vaccine in reserve to make sure people who have already gotten their first shot receive the required second one on schedule, three to four weeks later.

It’s a crisis that has everyday Americans thinking outside the box. The live music industry, sidelined completely by COVID-19, is offering to go back to work staffing vaccination mega-sites.

“The play isn’t just the venues. The important part, beyond the venues, is the people— because what do we do for a living?” Industry spokesman Michael Strickland told NewsNation Tuesday, “We handle crowds. We get people in and out quickly and safely.”

The pitch to help distribution sites has already been made to the federal government. Ideally, the staff would be ready just as new vaccine supplies hit the pipeline. President Biden says his administration would like to quickly ramp-up vaccinations to 1.5 million a day.