We teamed up with the Virginia Department of Health and hospitals around the state to conduct antibody testing to determine how many people may have been exposed to COVID-19. The result: As of mid-August, only 2% of Virginians had antibodies, suggesting that herd immunity is a long way off.
“We carefully follow case counts but need to recognize case counts are an underestimate of the true number of COVID infections,” said UVA project leader Eric Houpt, MD, the chief of our Division of Infectious Diseases and International Health. “If we use these data to project to today, we would project that as of February 2021, still under 20% of Virginians may have been exposed to the virus.”
That underscores the need for vaccination, Dr. Houpt said.
Overall, 2.8 times more Virginians had antibodies as of August than had been identified by the state’s PCR testing, Dr. Houpt and his collaborators report in a new scientific paper. That ratio is lower than many estimates predicting how much of the country’s population may already have antibodies to COVID-19.
Hispanic study participants had the highest exposure rate, with more than 10% having antibodies. Other groups with “notably higher” rates included Northern Virginia residents (4.4%), those aged 40 to 49 (4.4%) and the uninsured (5.9%).
“Virginians are still quite susceptible to this virus,” Dr. Houpt said. “We need to continue wearing masks in public and practice social distancing and hand washing. I encourage everyone who qualifies to get a COVID vaccine when they can.”