On April 30, the University of Arizona and the state of Arizona began an effort to test all frontline health care workers and first responders for antibodies to the virus that causes COVID-19. The first group includes 4,500 Pima County residents who are first responders, health care workers, and some members of the general public. The test will determine who has been exposed to the novel coronavirus and may have developed antibodies to protect against it. All individuals tested in phase 1 registered online and were required to wear a mask and have their temperature checked upon entry of the temporary clinic set up inside Tucson’s Cole and Jeannie Davis Sports Center. Testing for health care workers and first responders will expand to the remainder of the state on May 7; in total, 250,000 health care workers and first responders will be tested in Arizona. Read more about the test.