With focus on vaccines, COVID-19 testing is on the decline With focus on vaccines, testing is on the decline As COVID vaccination rates rise, testing is on the decline. That worries health officials because tests provide the best snapshot of public health. They don't want the vaccine to give a false sense of security. As vaccination rates rise, COVID-19 testing is slumping, and health officials are worried. In California, 3 out of 4 counties have seen their testing volume drop by at least 15 percent. "There used to be 5 or 6 people ahead of me, and lately it's down to no one, I just walk right in," said Brad Jann, getting tested at the Petaluma Fairgrounds on Friday evening.