New York City will require proof of vaccination for people going to indoor activities like restaurants, gym and performances, Mayor Bill de Blasio announced Tuesday.

The program will launch August 16 and will be enforced beginning September 13. The policy is one of the first of its kind in the United States; other large cities, like Los Angeles and San Francisco, that have seen an increase in COVID-19 cases as the Delta variant spreads have resumed requiring people to wear face masks indoors.

Several companies and public sectors have already announced mandatory vaccinations for employees. In New York City, health and hospital employees must be vaccinated or complete weekly COVID tests beginning this week. State employees and MTA workers must also follow the same rules starting on Labor Day.

All Broadway theaters will require audience members, performers, crew members and backstage staff to be vaccinated once venues reopen this fall. The Walt Disney Company will mandate that all salaried and non-union U.S. employees get vaccinated before returning to work. Netflix will require all actors and staff that come in close proximity to them, designated as Zone A crew members, be vaccinated on all U.S. productions. Employees at Google and Facebook must also be vaccinated before returning to their offices.

Last month, the Hollywood unions and major studios agreed on new COVID protocols that gave producers “the option to implement mandatory vaccination policies for casts and crew in Zone A on a production-by-production basis.” However, other workers in Zones B, C and D cannot be forced to get vaccinated.