The rapid development of coronavirus vaccines, including one that may be weeks away from federal approval, offers the best hope yet for an end to the pandemic.

But producing, distributing and administering the vaccine in a country with nearly 330 million people will be its own, unprecedented challenge and one that appears pretty daunting at this point.

States have to craft and then implement distribution plans, and to do that they need money from the federal government. But the level of preparation across the country is uneven, according to analysts who have been reviewing those state plans , and the federal funding is a fraction of what it needs to be.

States will require anywhere from $6 billion to $10 billion to handle vaccine distribution, according to advocates and public health officials. Most of that money will have to come from Congress, and leaders from both parties have said they want the next COVID-19 relief bill to include that funding.

But negotiations over that bill broke down before the election, because Republicans want a smaller relief package overall. Its not clear when talks will restart or where they will lead even though time is very much of the essence.

Every month that additional support gets delayed, it will be that much harder to get vaccines out in an equitable and efficient way, Joshua Michaud , associate director for global health policy at the Henry J. Kaiser Family Foundation , told HuffPost. And the earlier you get the vaccines out, the more lives you save and the faster people can get their lives back to normal.

Heres a look at the challenges ahead:

Getting Vaccine Approval Is Just The First (Big) Step

Pfizer (with its German partner BioNTech) a week ago became the first manufacturer to seek emergency authorization of its novel coronavirus vaccine, following trials the company said showed 95% efficacy. Approval could theoretically come as early as Dec. 10, when the committee advising the U.S. Food and Drug Administration meets to consider it, although a top agency official told CNN on Friday that it will be a matter of weeks. It could be from days to weeks.

Pfizer has already started manufacturing the vaccine and says it will have more than 6.4 million doses ready to go once the FDA gives the OK. By the end of the year, Pfizer says, it could have as many 25 million doses out the door, which would be enough to reach about 12.5 million people. (The vaccine requires two doses several weeks apart.)

Moderna, which is developing a vaccine that uses the same basic mechanism, has announced that it is getting similar results and plans to seek authorization shortly. AztraZeneca, Johnson & Johnson and Novartis say they are not far behind.

Having such a promising vaccine for a novel pathogen ready to go less than one year after the disease appeared in the U.S. would be a remarkable and historic scientific achievement made possible by cooperation between the private and public sectors, including the Trump administrations $18 billion Warp Speed initiative.

It will take similar cooperation to produce and distribute the vaccines once they are ready. Trump officials have said they have been working to make sure the manufacturers get the supplies they need, from vials and plungers to the chemical ingredients for the vaccine itself.

Meanwhile, Defense Department logistics officials have been making sure plans are in place to get the vaccine from manufacturing plants scattered across the U.S. to the facilities that will be administering them. Most of the manufacturers are contracting with pharmaceutical supply and distribution company McKesson ; Pfizer is handling distribution on its own.

On a press call last week, Trump administration officials said they had been conducting tabletop exercises and dry runs to make sure the distribution channels are clear and working which is exactly what they should be doing. Pfizer, for its part, has been developing special shipment containers that can keep the vaccines at the cold temperatures they require for storage.

But until vaccines start rolling out of plants and onto trucks and planes, its difficult to know whether the planning has been adequate and how well the process will work. Likewise, its hard to know whether the companies can really produce vaccines at the mass scale and rapid timeline theyve promised, especially because the Pfizer and Moderna vaccines, if approved, will be the first ever to use messenger RNA (mRNA).

States Hold The Keys Once The Vaccines Get There

How the vaccines get into the arms of Americans is the next big question.

It is up to the states to make plans for distribution, though they are supposed to follow federal guidance about prioritization. Front-line health workers will get the first shots, followed by other essential workers and the most vulnerable populations, including residents of long-term care facilities.

As vaccines become more plentiful, other populations will get access, starting with other high-risk groups, such as those with underlying medical conditions, and then finally to the population as a whole.

At the direction of the Centers for Disease Control and Prevention, states have been developing and filing plans for exactly how they would break down those priority groups. They must decide which categories of workers are essential and which population groups are high-risk, for example, and their plans must include who will administer the vaccines to different groups and how.

Health care providers, like hospitals and clinics, will generally take on responsibility for vaccinating their workers. Some have already announced they plan to have the vaccine ready for employees by Dec. 12, two days after the FDA meeting, just in case approval comes right away.

CVS and Walgreens will also be administering vaccines in their stores and at pop-up clinics, which is something they already do routinely for flu shots. Working with Warp Speed and state officials, they have already said they will be able to administer vaccines inside nursing homes and other long-term care facilities.

CVS officials told HuffPost the company should be able to get vaccines out to long-term care facilities as soon the supply comes in and then add the ability to offer in-store shots once that supply is available, as well. It has even been developing digital tools, including a website and text-messaging system, to make sure people remember to get the second dose of the vaccine.

The bottom line is, were going to bug the hell out of you to make sure that you get that second shot, so the vaccination doesnt go to waste, said T.J. Crawford, head of external affairs at CVS.

CVS says it will be able to deliver as many as 20 million to 25 million vaccinations a month; a Walgreens official could not provide a figure for the chain, but most likely its capacity is of a similar magnitude.

That would be a lot of people and yet, still not nearly enough to reach the entire country in a short span of time, especially since both the Moderna and Pfizer vaccines require two doses.

And even if CVS and Walgreens can administer the vaccine as seamlessly as they hope, there are going to be parts of the country, including rural and some low-income areas, they dont reach easily.

All of that means the states still have a lot to do on their own.

States Have A Lot To Do And Many Arent Ready

States can work through any number of intermediaries, from local public health departments and clinics to the Red Cross and National Guard, in order to administer the vaccines.

But they need to be making their plans now, and some are a lot further along in that process than others, according to an analysis that the Kaiser Foundation published in mid-November. It found, among other things, that less than half the states had estimated how many people belong in each priority category and that less than one-third had estimates for the number of vaccine providers.

Our review shows that states are all over the map in terms of their readiness to handle vaccine distribution, said Drew Altman , the foundations president and CEO. There is time to provide the resources and guidance they need, but not a lot of time.

Planning will be particularly difficult for rural communities, as a recent investigation by ProPublica found. Among the issues already worrying state officials is how to handle the Pfizer vaccines super-cold storage requirements when trying to deliver the vaccine to hard-to-reach areas.

States will also have to pay for the facilities and staff time. In all likelihood, they will also have to train a bunch of new people on how to give shots, if not right away then later on once the supply from manufacturers increases dramatically.

There is no way the states would be able to provide this magnitude of effort without federal funding, Juliette Kayyem, a former Homeland Security official in the Obama administration and faculty director at Harvards Kennedy School of Government, told HuffPost.

The realities of vaccine production mean it will be weeks and probably months before the supply really tests the capacity of states to administer it widely. But whether the states are ready at that point may depend on what Congress does right now.

CORRECTION: An earlier version of this article misidentified CVS spokesman T.J. Crawford.

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