Mayor Bill de Blasio said Monday that four school vaccination sites were delayed in getting their assigned vaccine supply, and that long lines were at 12 different sites in Brooklyn and Manhattan.

In New York City, almost 17,000 kids between the ages of 5 and 11 have received the Pfizer vaccine since the shot was approved by the Centers for Disease Control and Prevention last week, according to the mayor.

Through next Monday, every public school that serves kids in the 5 to 11 age range will have vaccines available for at least one day, and News 12 is hearing from the mayor’s office that the focus is to make sure more of the vaccine is available in the spots where the demand is higher.

More than 200 schools will be administering vaccines today. Click here to find the nearest school vaccine clinic near you.