(YWN) Mayor Bill de Blasio announced on Tuesday, August 3, that New York City will require proof of vaccination for people participating in indoor activities, including at restaurants, gyms and performances—his latest attempt to spur more vaccinations. The mandate also applies to workers at those places.

The policy is believed to be the first of its kind in the United States.

The program will start later this month, and after a transition period enforcement will begin in mid-September, when schools are expected to reopen and more workers could return to offices in Manhattan.