LOS ANGELES (KTLA) — California will require proof of vaccination or a negative coronavirus test to attend indoor gatherings of 1,000 or more people starting next month, a move the state says is the first of its kind in the nation.

The new rules, announced Wednesday, will take effect Sept. 20. They replace current standards that call for COVID-19 vaccine verification or a negative test for events with 5,000 or more attending, according to guidance from the California Department of Public Health.

A negative coronavirus test must be taken within 72 hours of the event’s start to be accepted.

Additionally, self-attestation will no longer be accepted to verify vaccine status. Attendees will have to submit some form of proof, such as their vaccine card, QR code or a photo of their vaccine card.

The new rules will remain in place through at least Nov. 1.

The move is aimed at encouraging more people to get vaccinated while decreasing the potential for the highly contagious delta variant to spread.

“The delta variant has proven to be highly transmissible, making it easier to spread in large crowds where people are near each other for long periods of time,” Dr. Tomás J. Aragón, California’s public health officer, said in a statement. “By requiring individuals to be vaccinated, or test negative for COVID-19 at large events, we are decreasing the risk of infection, hospitalization and death.”

More than 14,300 new infections and 90 fatalities were reported statewide Tuesday. The virus is largely spreading among unvaccinated people, whose case rate statewide is 500% higher than that of vaccinated individuals, CDPH said.

Meanwhile, around 79% of eligible Californians had been vaccinated as of Wednesday.

Check back for updates on this developing story.