U.S. health officials have set the stage for a nationwide COVID-19 vaccination campaign to protect children younger than five years old. They invite state officials to order vaccines before they are approved.

Pfizer’s coronavirus vaccination is being administered to children as young as 12 years old in the United States. Federal officials will discuss in the coming weeks making lower-dose versions of the vaccine available to the nation’s 28 million children aged 5-11 years.

The Centers for Disease Control and Prevention sent a seven-page document this week to help cities and states prepare. It contains guidance on how to establish expanded vaccination programs.

It notes that pharmacies in all states can administer COVID-19 shots for children. However, it clarifies that children under 12 years old should only be given doses made and packaged for them.

However, it doesn’t address some of the more difficult questions such as how school-based clinics can be relied upon or whether children should be required to have them shot as a condition for school attendance.

Older adults are more likely to die and be hospitalized from the disease than children. However, some children are at greater risk of severe illness. According to the American Academy of Pediatrics, more than 540 U.S. kids have died from COVID-19.

Importantly, experts believe that vaccines for children can reduce the spread of virus to adults.

Pfizer and BioNTech, its German partner, are the most advanced in research on vaccine use in children younger than 12 years old. A two-dose vaccine series, which is one-third as powerful as the one given to people over twelve years old, is safe and effective for children aged 5 to 11.

A panel of independent experts that advises Food and Drug Administration will discuss the evidence publicly at a meeting scheduled for late October. A different expert panel advising CDC would discuss the issue in early November if the FDA approves kid-sized doses. Then, the CDC will make a recommendation.

According to Dr. Marcus Plescia (chief medical officer of the Association of State and Territorial Health Officials), it’s still not clear how many people will receive shots for their children right away.

He said, “We’re going be having potentially a very hectic, and possibly slightly chaotic time” at first.

He said that there won’t be as much demand for shots now than when they were first made available to adults.

According to the new CDC guidelines, shots should be administered at the offices and clinics of family-practice physicians, pediatricians, and pharmacies.