According to study results released Friday by the U.S., child-sized doses of Pfizer’s COVID-19 vaccine seem safe and almost 91% effective in preventing symptoms in children aged 5-11 years old.

If regulators approve, the shots could start in November and the first child in line would be fully protected by Christmas. This would be a significant expansion of the nation’s vaccine drive that covers approximately 28 million elementary-aged children.

Pfizer posted details of its study online. Later in the day, the Food and Drug Administration would post its own review of Pfizer’s safety and effectiveness data.

Next week, FDA advisors will debate the evidence in public. If the agency authorizes the shots itself, the Centers for Disease Control and Prevention (CDC) will decide who should get them.

Pfizer full-strength shots are already approved for those 12 and older. However, many parents and pediatricians are anxiously waiting for protection for their children as they face rising infections and record hospitalizations from the extra-contagious Delta variant.

Biden’s administration purchased enough doses in kid-size vials, with special orange caps to differentiate them from the adult vaccine. This will be sufficient for all children aged 5 to 11. Millions of doses and kid-sized needles will be shipped to the nation if the vaccine is approved.

Already, more than 25,000 primary care providers and pediatricians have signed up for the shot.

Pfizer studied 2,268 children aged 5-11 who received two doses of the low-dose vaccine or a placebo three weeks apart. Each dose was equal to one-third of the amount given for teens and adults.

Based on 16 COVID-19 cases from children who received dummy shots, researchers calculated that the low-dose vaccine was almost 91% effective. This is compared to three cases for vaccinated kids. None of the children suffered from severe illness, but the vaccines produced milder symptoms than those who were not vaccinated.

The majority of the study data was collected in America during August and September when the Delta variant was the dominant COVID-19-strain.

Additionally, the coronavirus-fighting antibodies levels of young children who received low-dose shots were just as strong than those of teens and young adults who had regular-strength vaccines.

Another encouraging piece of news was that the CDC earlier this week reported that Pfizer vaccines were 93% effective in preventing hospitalizations among 12- and 18-year-olds, despite the spike in the delta variant over the summer.

Pfizer’s study on younger children showed that low-dose shots were safe and had similar or fewer temporary side effect like fever, sore arms, or achiness as teens.

Although the study was small enough to detect rare side effects such as heart inflammation, which can sometimes occur after the second dose, it is not large enough for young men.

According to the CDC, children are at lower risk of serious illness and death than those who are older than them. However, COVID-19 has claimed the lives of more than 630 Americans aged 18 or under. The American Academy of Pediatrics reports that nearly 6.2 million children have been infected by the coronavirus. This is more than 1.1million in just six weeks, as the delta variant surged.

Moderna is also studying COVID-19 shots with elementary-school-age children. Moderna and Pfizer are also studying children as young as 6 months old. More information will be available later in the year.