A woman walks by a sign reading 'Masks Are Required' outside a shopping mall on August 3, 2021, in San Francisco.
CNN  — 

San Francisco became the the first major US city to mandate proof of full vaccinations for certain indoor activities Thursday.

City residents age 12 and older will now be required to show proof they have been fully vaccinated against Covid-19 in order to enter indoor restaurants, bars, gyms and theaters, as well as large event spaces with at least 1,000 people, according to an announcement from Mayor London Breed.

San Francisco Mayor London Breed announced the measures Thursday.

The new mandate is scheduled to go into effect August 20.

“We know that for our city to bounce back from the pandemic and thrive, we need to use the best method we have to fight COVID-19 and that’s vaccines,” Breed said in a statement. “Many San Francisco businesses are already leading the way by requiring proof of vaccination for their customers because they care about the health of their employees, their customers, and this City.”

Last month, hundreds of bar owners in the city said they would require patrons to provide proof of vaccination status or a negative coronavirus test result to enter. San Francisco was also one of many cities in the Bay Area to mandate face coverings in indoor public places – regardless of vaccination status. The order affected more than 7 million Bay Area residents.

Business owners were supportive of the city’s latest mandate.

“These increased provisions hopefully will expedite all public gathering places ability get back to doing what we all love – being a space for community in service to all San Franciscans,” said Casey Lowdermilk, co-founder of the San Francisco Venue Coalition, an organization looking to keep businesses safely open during the pandemic.

About 78% of San Francisco residents are vaccinated, the news release from the city said. Despite that, the city’s current Covid-19 test positivity rate is 5.6%, surpassing the rate from the peak of the winter surge, which was 5.2%, the release said.

“In this phase of the pandemic, we must optimize the powerful tool of vaccines to protect us as we fully reopen to business,” said Dr. Grant Colfax, San Francisco’s director of health. “These past few weeks have demonstrated how important it is that everyone eligible is vaccinated as we resume normal activities.”

The San Francisco health order also beefs up a state order mandating vaccines for health care workers by extending the directive to pharmacists, dental offices, home health aides and residential care centers.