https://www.siliconvalley.com/2021/08/18/california-expands-vaccine-proof-covid-test-order-for-indoor-events/

California health officials Wednesday expanded the requirement for vaccination or a negative COVID-19 test for those attending large indoor events as the state continues to battle rising infections from the highly contagious delta variant of the virus.

The state had already required either vaccination or a negative COVID-19 test within 72 hours to attend events of 5,000 people or more. Wednesday’s order expands that to gatherings of 1,000 people or more, and requires proof of full vaccination rather than the “self attestation” of having been vaccinated that had been allowed.