Nearly 17 million people — about five times more than official counts — may have had undiagnosed COVID-19 infections in the U.S. during the first few months of the pandemic, according to research published June 22 in Science Translational Medicine.
Researchers conducted spike protein antibody tests from 8,058 participants who were previously undiagnosed with COVID-19. Blood samples were collected between May 10 and July 31, 2020.
Of those, 304 had COVID-19 antibodies, translating to 4.8 million undiagnosed infections for each diagnosed case during this time period. This suggests there were potentially 16.8 million undiagnosed COVID-19 infections by mid-July — about five times higher than the 3 million official diagnosed cases at the time, according to the findings.
A higher proportion of Black participants (14.2 percent) had COVID-19 antibodies, compared to white (2.4 percent) and Asian (2 percent) participants.
"Our data suggests a larger spread of the COVID-19 pandemic in the United States during the first six months than originally thought," researchers said. "Our findings have implications for understanding SARS-CoV-2 spread, epidemiological characteristics of spread and prevalence in different communities, and could have a potential impact on decisions involved in vaccine rollout."
To view the full findings, click here.