On Dec. 14, 2020, a months long study to determine the number of Houstonians carrying COVID-19 antibodies revealed infections may have been four times greater than viral tests showed, according to collaborators at the Houston Health Department, Rice University and Baylor College of Medicine.

Samples from 678 residents collected between Sept. 8-19 showed a higher proportion of individuals with COVID-19 antibodies lived in high-positivity-rate areas (18%) of the city than those who lived in low-positivity-rate areas (10%).