In California, a pair of scientific teams reported this week that blood tests found antibodies for the coronavirus in people at dozens of times the known rate of infection. The findings appear to suggest that most cases of COVID-19 are mild, making the disease’s mortality rate much lower than previously reported. But many researchers are skeptical, warning the findings were first presented to the press and haven’t been peer-reviewed; they’re also based on new serology tests that have an unknown rate of false positives.