Leaders of the Trump administration's Operation Warp Speed spent months working with states and cities to improve their coronavirus vaccine rollout plans, and helped set President Joe Biden's administration on a glide path to its goal of vaccinating 100 million people in 100 days, according to current and former operation officials who spoke with National Review.

Those officials pushed back on Biden administration members who have both publicly and privately bashed their predecessors for leaving "no coronavirus vaccine distribution plan to speak of." The Biden officials are simply "passing the buck" and trying to lower expectations, two Trump administration officials said.

Last week, CNN White House correspondent MJ Lee published a story titled "Biden inheriting nonexistent coronavirus vaccine distribution plan and must start ‘from scratch,’ sources say." It included quotes from anonymous Biden administration officials saying things like "there is nothing for us to rework" and that they were starting from "square one." Though Dr. Anthony Fauci has publicly refuted the claim, Biden officials have continued to imply it.

"The sad part is the last administration didn’t leave anything. They didn't leave a plan,” Biden senior adviser Cedric Richmond told CNN on Saturday. On Meet the Press, Biden chief of staff Ron Klain said “the process to distribute the vaccine, particularly outside of nursing homes and hospitals out into the community as a whole, did not really exist when we came into the White House.”

The White House has set a goal of 100 million vaccinations in Biden's first 100 days, though CDC director Dr. Rochelle Walensky said Sunday that she didn't know "how much vaccine we have," a statement echoed by Biden press secretary Jen Psaki on Monday.

"The confusion around this issue — which, we acknowledge, there is some confusion — speaks to a larger problem, which is what we're inheriting from the prior administration," Psaki said. "Which is much worse than we could have imagined."

But per vaccination data from Bloomberg, the U.S. has now hit 1 million vaccinations for four days in a row, with a rolling seven-day average of 1.2 million. And on Monday, Biden himself said he hoped to raise the threshold to 1.5 million soon.

The new administration’s ability to hit its daily target immediately after the benchmark was set is evidence that they inherited a workable plan from the Trump administration, according to current and former officials.

"We provided the Biden team over 300 transition meetings, including the very first one on Warp Speed which I kicked off myself,” former Health and Human Services chief of staff Brian Harrison told National Review. “The idea that they’re walking in, having no clue what was going on, is absolutely preposterous."

Another former senior administration official noted the difference between the distribution of vaccines – the logistical efforts to transport the vaccines to the proper locations – and the actual administration of the vaccines, or actually getting needles into arms.

The former official described the distribution plan, which is being managed by U.S. Army general Gustave Perna, as "extraordinarily detailed" and "comprehensive."

"It's gone flawlessly," the former official said. "Like, out of tens of thousands of deliveries under extreme cold storage conditions, I think three out of like 30,000 didn't make it to the right place at the right time. So, it's a 99.99 percent success rate of shipping to the right place at the right time in the right quantity, under the right conditions."

As for the actual administration of the vaccine, officials said that there were also plans in place for rollout, led by the U.S. Centers for Disease Control and Prevention.

"CDC was the one who volunteered — not volunteered, asserted — itself to the task, and said that they were going to be in charge of this because they were in charge of pandemic influenza distribution and allocation," one former senior HHS official said.

The former official added that the incoming administration’s insistence on blaming the outgoing one for challenges associated with vaccine distribution amounts to "playing politics with public health."

"They're shifting blame. That’s the most polite way I could describe it. But I’ll tell you that the guys at Warp Speed were pushing the CDC really hard to basically demonstrate that the plans were more than just paper," the official said. "They pushed them as hard as they could, but again, CDC was strident in its view that they’re the experts. They’re the ones with the relationships with the states. They’re the ones who could do this and that."

"It’s disgraceful that the CDC is pointing its finger at Warp Speed, when CDC was the one that said that they were in charge and basically said they were the one responsible party," he continued. "It’s passing the buck, and I just think that’s disgraceful."

A disagreement over governing philosophy accounts for much of the division between the vaccine rollout plan implemented by the Trump administration and the one preferred by the Biden team. The Biden team believes in centralizing control of the rollout under the federal government, while the Trump team sought to empower the states and public health jurisdictions.

"There was this very big feeling in the Trump administration we need to leave this to the states," one senior administration official involved with Operation Warped Speed told National Review. "There was fear of we don't want to dictate to the states of how we do this, but we can get it there. If they tell us where to send it, we can deliver it."

Under the Trump administration, there wasn't one vaccine rollout plan, but rather 64 plans, one from each of the nation's public health jurisdictions. Those plans were crafted, starting in mid-September, based on a 60-page operating book provided by the CDC, which gave guidance to local officials about operations, logistics, information technology, and storage requirements, among other things. The jurisdictions turned in their vaccine administration plans in mid-October, one former official said.

"We actually created a rating system that has seven criteria for each one. And we rated them as red, yellow and green. And where we saw yellow and red, we worked with the states. We even sent strike teams out to the states and jurisdictions to help them get their plans well developed," the former official said.

The planning process wrapped up in early December, the former official said.

"They were all in good shape," the former official said. "I don't want to say all the reds turned to green, but they certainly all turned to yellow. And we felt pretty good about them. There was an immense amount of planning that went on over several months' time."

The states that have been most successful were those whose leaders were engaged from the beginning, and those who worked well with local community leaders, the former official explained.

"I can tell you the single biggest difference, and that is, was the governor engaged in the fall or wasn't he or she?" the former official said. "You had some of them front and center taking notes, asking questions. … Other governors didn't give a crap. Some didn't show up to a single governors call when we discussed all of this."

There were some hurdles and unexpected challenges, the former official acknowledged. For one, the CDC's Advisory Committee on Immunization Practices (ACIP) provided guidance over the winter, recommending that front-line workers and people who live in congregant settings be prioritized. Some jurisdictions applied those guidelines so rigidly, that when some of the intended vaccine recipients declined to take the vaccine, there was no backup plan for how to distribute the extra doses, the former official said.

"When ACIP came out with its recommendations, I would have had every doctor on television saying, 'Guys, these are just recommendations. You should do what's best for your states,'" the former official said.

The former official also said Pfizer's vaccine rollout was slower than expected, and the federal government received fewer doses than initially planned.

"We probably shouldn't have had as much confidence in that globally respected pharmaceutical company and its CEO who made promises to us that they didn't keep," the former official said.

As for the Biden administration's claims that there was no vaccine rollout plan, the Trump administration's rollout was already hitting the goal of distributing 1 million doses daily.

"It appears to me they are lowering expectations so they can look like they're heroes," the former official said, adding, "I think they're both naïve and a little bit arrogant about what they believe the federal government can do to make this any better than what it has."

One pharmaceutical adviser working with Operation Warp Speed said that what has been accomplished already has been "remarkable, and hopefully will continue to improve."

"I think that we have accomplished something that has never been accomplished before," said the adviser, who is still working with the project. "There are things that could have worked better, of course. When you do something like this, you can always point at something that could have been better."