With the authorization of the Pfizer COVID vaccine for kids, both CVS (CVS) and Walgreens (WBA) have announced that they will begin administering the shot to children as soon as this week.

CVS said it will begin giving the Pfizer vaccine to children aged 5 to 11, starting on Sunday, while Walgreens will begin administering the shot for kids on Saturday.

The Food and Drug Administration authorized the Pfizer-BioNTech vaccine for children aged 5 to 11 on Tuesday, while the Centers for Disease Control and Prevention issued new guidelines for the shot for this age group the same day.

According to Walgreens, the Pfizer COVID vaccine for kids, which is administered in a lower dose, will begin arriving at select pharmacies this week.

Parents can schedule appointments for their children to get inoculated online at Walgreens.com/ScheduleVaccine or through the Walgreens app or by calling 1-800-Walgreens.

The retailers said more appointments will open up in the coming weeks as more doses of the vaccine become available.

Children who receive the Pfizer COVID vaccine will need to receive a second dose of the shot at least three weeks following their first dose to complete their vaccine regime for full protection against the virus, Walgreens said.

Walgreens also said that it “highly” encourages parents to make an appointment for their child to get vaccinated. Parents will need their child’s date of birth at the time they make the appointment, and a parent or guardian must be present when the shot is administered. There will also be a 15-minute observation period after inoculation of the vaccine.

Children will also receive an activity sheet, stickers, an opportunity to print a free 5xt photo to capture the moment and free Tootsie Pops, Walgreens said.

Shot appointments at CVS can be scheduled on the company’s COVID Vaccine Online Scheduler.

CVS requires that a parent accompany children aged 5 to 15 at their shot appointment. All children will be required to remain in the pharmacy area for at least 15 minutes after receiving their COVID vaccine for observation.

Immunizers will also be on-site at pharmacies to answer any questions that parents may have about the kids’ COVID shot, CVS said.

The Moderna and Johnson & Johnson COVID vaccines are authorized for those aged 18 and older. A Moderna vaccine for children is being reviewed by the FDA.

As of Wednesday at 10:59 a.m. ET, shares of Walgreens were trading at $49.07, up $1.32, or 2.76%, while shares of CVS were trading at $95.79, up $4.64, or 5.09%.

A Walgreens store in Riviera Beach, Florida. Joe Raedle/Getty Images