Researchers surprised: 20% of Chicagoans in blood-test study came up positive for coronavirus antibodies – Chicago Tribune

The SCAN study, launched in late June, set out to test about 3,000 people in 10 Chicago ZIP codes, and so far more than 1,000 tests have been analyzed, McNally said. Researchers are finding some differences in exposure rates among the ZIP codes but said they need to gather more test results before reaching any conclusions.