COVID-19 IgG/IgM antibody testing in Los Angeles County, California

Evidence suggests that asymptomatic and mild SARS-CoV-2 infections comprise > 95% of all cases. Developing a test that indicates past infection and possible immunity against the virus is important. We administered 244 antibody tests to three groups of high-risk population. The test consisted of an IgG component and an IgM component. The overall IgM/IgG positivity for patients with none, mild, moderate, and severe symptoms were 21.1%, 21.8%, 14.2%, and 26.9%, respectively. Those with moderate or severe symptoms were no more or less likely to have positive antibody tests than those with no or mild symptoms.

Automated summary

Evidence suggests that over 95% of all SARS-CoV-2 cases are asymptomatic or mild infections. Developing a test to indicate past infection and potential immunity is crucial. A study administering 244 antibody tests to high-risk populations found that moderate or severe symptom patients were no more or less likely to have positive antibody tests compared to those with no or mild symptoms.