CHARLOTTESVILLE, Va. (WDBJ / UVA Release) – UVA researchers concluded that collective immunity in Virginia “is currently not a plausible means of ending the COVID-19 pandemic”. But they believe their discovery reinforces the importance of vaccines, saying that without them, collective immunity is much more distant.
The finding is based on a study in which the statewide blood test for COVID-19 revealed that only 2% of Virgos had antibodies to the virus in mid-August 2020, just a few months after the pandemic began and before it vaccines were available.
Read the full study here.
About 2.8 times more Virgos had antibodies than those identified by the state’s PCR test, according to UVA researchers. This proportion is lower than many estimates that predict how much of the country’s population may already have COVID-19 antibodies.
Participants in the Hispanic study had the highest exposure rate, according to UVA, with more than 10% having antibodies. Other groups with “notably higher” rates included residents of Northern Virginia (4.4%), those aged 40 to 49 (4.4%) and the uninsured (5.9%). The prevalence by CEP ranged from 0% to 20%. Often, neighboring postal codes have produced dramatically different results, say the researchers.
“We carefully follow the case count, but we need to recognize that the case count is an underestimation of the true number of COVID infections,” said Eric Houpt, MD, head of the UVA Health Division of Infectious Diseases and International Health. “If we used this data to design today, we would project that, in February 2021, even less than 20% of Virgos may have been exposed to the virus.”
COVID-19 antibody test
To better understand how COVID-19 is widespread in Virginia, UVA Health and the Virginia Department of Health have partnered with major hospitals across the state. The researchers tested the blood of 4,675 outpatients in five health systems: UVA Health in the northwest, Inova Health System in the north, Sentara Healthcare in the east, Carilion Clinic in the southwest and Virginia Commonwealth University in the center. Each center enrolled up to 1,000 residents, aged 18 or over, who were not being assessed for possible COVID-19 infections. The participants combined the composition of age, race and ethnicity of each region, according to UVA
Among the 101 participants who had COVID-19 antibodies, 42 were Hispanic. People with antibodies were more likely to live in multi-family units and had contact with a patient confirmed to have COVID-19, the researchers report.
The researchers estimated that approximately 66% of the infections detected were asymptomatic.
Previous studies of COVID-19 suggested that confirmed cases may represent only a small percentage of people who have been infected. Estimates of total unrecognized infections ranged from six times confirmed cases to 53 times, so Virginia’s results were lower in comparison, according to UVA.
“Virgos are still very susceptible to this virus,” said Houpt. “We need to continue wearing masks in public and practice social detachment and hand washing. I encourage everyone who is eligible to receive a COVID vaccine when they can. “
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