Dashboard Tracking Coronavirus Antibody Tests Suggests 19 Million Americans May Have Been Infected

Academics have revealed a new online dashboard that provides a better understanding of the true scope of the global COVID-19 pandemic.

Citizens across the world have turned to such tools as a way to track daily infections of the novel coronavirus, including the popular dashboard maintained by Johns Hopkins University that shows confirmed cases and deaths by country or region.

Now, experts say that despite existing tools still being pivotal in tracking the outbreak, there are additional insights to be gleaned by logging antibody test results, potentially an indicator how many people have built up protection from reinfection.

That's what the new dashboard does. Known as SeroTracker, it records seroprevalence, which is the number of people previously been infected with SARS-CoV-2—the virus that causes COVID-19—based on antibody, or "serology," testing.

The tool indicates the U.S. is currently at 5.8 percent seroprevalence, based on 15,993 administered antibody tests. When compared to the approximate population of the U.S., the results could mean up to 19 million U.S. residents have been infected.

A study related to the dashboard has been published in The Lancet.

Although the researchers behind the project say the tool's estimates do not necessarily apply to entire populations, the figure roughly matches with CDC serology test analysis in June which suggested around 20 million Americans may have had COVID-19. The figures indicated U.S. residents had the illness, but did not show symptoms.

"Our... estimate right now is that for every case that was reported, there actually were 10 other infections," CDC director Robert Redfield was quoted by the BBC as saying. "We probably recognized about 10 percent of the outbreak by the methods that we use to diagnosis between the March, April and May."

While viral tests hunt for current infections, antibody testing checks the blood for signs that a person has built up proteins needed to protect against getting the disease again. Antibody tests can be crucial in logging anyone who was asymptomatic.

Scientists are still working to grasp COVID-19 immunity, and it is unclear if antibodies from SARS-CoV-2 fight off future infections or how long such protection will actually last, the CDC has said.

SeroTracker is being maintained by the Public Health Agency of Canada and hosted at the University of Calgary's Centre for Health Informatics.

The team behind the project said all individuals with antibodies specific to SARS-CoV-2 have been exposed to the virus, so tracking that testing shows any differences in past exposure between regions or demographics, and used to estimate death rates.

"As the initial phase of the COVID-19 pandemic passes its peak in many countries, serological studies are becoming increasingly important in guiding public health responses," the team wrote in The Lancet paper. "Antibody testing is crucial for monitoring the evolution of the pandemic, providing a more complete picture of the total number of people infected with [COVID-19]."

Similar to the Johns Hopkins University tool, SeroTracker lets users see seroprevalence estimates on a map. The data is sourced from articles and government reports about seroprevalence and collated by a team of doctoral and medical students.

"Filtering for... seroprevalence estimates in the general population yields studies in 12 countries," the paper said. "Comparing estimates to diagnostic testing data suggests SARS-CoV-2 has infected many more individuals than case counts indicate."

While clinical tests for a vaccine to COVID-19 remain ongoing, scientists say there is no known cure for the novel coronavirus. It is believed to spread via human to human contact, including respiratory droplets when a person coughs or exhales.

According to Johns Hopkins data, America now has the most number of cases in the world—at least 4.7 million—and it has been tied to over 156,000 U.S. deaths.

U.S. health officials have advised the public to maintain social distancing and wear face coverings when in close proximity with others. "A mask may not protect the wearer, but it may keep the wearer from spreading the virus to others," the CDC says.

coronavirus testing
A coronavirus antibody rapid serological test kit showing a negative result for no antibodies is displayed at an antibody testing site, July 26, 2020 in San Dimas, California. ROBYN BECK/AFP/Getty