D.C.’s walk-up coronavirus vaccination sites opened to 16- and 17-year-olds for the first time on Friday, and the health department said the city is preparing to offer walk-up vaccinations to children as young as 12 soon, if the FDA approves the Pfizer vaccine for young teens as expected.

Teenagers can only get the Pfizer vaccine, not Moderna or Johnson & Johnson, which means their options are limited to six of D.C.’s walk-up sites. They can also get vaccinations at commercial pharmacies including CVS, Safeway, and Walgreens; at pediatric clinics run by Children’s National Hospital; and some other medical providers.

Preetha Iyengar, an epidemiologist in the city health department, told the D.C. Council at a meeting Friday that the health department was working with the pharmacists who run the walk-up sites on training for administering vaccinations to younger children, which can involve more steps than vaccinating adults such as verifying age and parental consent.

Iyengar said the city is still determining which sites will open to children under 16, and it may take a few days after the FDA approves the shot for younger teens before the District begins administering it.