WASHINGTON (NewsNation Now) — The federal government outlined a plan Wednesday to make vaccines for COVID-19 available for free to all Americans.

In a report to Congress and an accompanying “playbook” for states and localities, federal health agencies and the Defense Department sketched out complex plans for a vaccination campaign to begin gradually in January or possibly later this year, eventually ramping up to reach any American who wants a shot. The Pentagon is involved with the distribution of vaccines, but civilian health workers will be the ones giving shots.

The campaign is “much larger in scope and complexity than seasonal influenza or other previous outbreak-related vaccination responses,” said the playbook for states from the Centers for Disease Control and Prevention.

Among the highlights:

— For most vaccines, people will need two doses, 21 to 28 days apart. Double-dose vaccines will have to come from the same drugmaker. There could be several vaccines from different manufacturers approved and available.

— Vaccination of the U.S. population won’t be a sprint but a marathon. Initially there may be a limited supply of vaccines available, and the focus will be on protecting health workers, other essential employees, and people in vulnerable groups. The National Academy of Medicine is working on priorities for the first phase. A second and third phase would expand vaccination to the entire country.

— The vaccine itself will be free of charge, and patients won’t be charged out of pocket for the administration of shots, thanks to billions of dollars in taxpayer funding approved by Congress and allocated by the Trump administration.

— States and local communities will need to devise precise plans for receiving and locally distributing vaccines, some of which will require special handling such as refrigeration or freezing. States and cities have a month to submit plans.

Some of the broad components of the federal plan have already been discussed, but Wednesday’s reports attempt to put the key details into a comprehensive framework. Distribution is happening under the umbrella of Operation Warp Speed, a White House-backed initiative to have millions of doses ready to ship once a vaccine is given what’s expected to be an emergency use approval by the Food and Drug Administration. Several formulations are undergoing final trials.