LAS VEGAS (AP) - The Nevada State Public Health Laboratory plans to begin antibody studies this month to better understand how many people have been infected by the new coronavirus and how many may have some immunity.
Antibody tests offer what Mark Pandori, public lab director at the University of Nevada, Reno School of Medicine termed “that time-travel element that you rarely get in science.”
“We’re going to get a handle on how dangerous this virus was - and is,” Pandori told the Las Vegas Review-Journal.
Unlike diagnostic tests that determine current infection by the COVID-19 respiratory illness, antibody tests aim to detect immune system proteins indicating previous infection.
Identifying past infection, including in people who showed no symptoms, can help public health officials calculate a more accurate rate of death from the disease.
A more accurate picture of how far the virus has spread helps communities plan ahead, Pandori said.
The studies come as policymakers grapple with risks of reopening stores, casinos and schools. Some tout antibody testing as a key to people returning to work.
Health care providers have begun ordering tests from private labs, although it’s not known whether the presence of antibodies indicates immunity from reinfection, or for how long.
Pandori said the state lab in Reno plans to launch four or five antibody studies within weeks involving 400 people each, focusing on the general public, front-line health care workers and emergency responders.
Health officials believe more people have contracted the virus than have had cases confirmed by COVID-19 tests, because many with mild illness or no symptoms do not get tested.
In addition, an initial shortage of testing materials meant that not everyone wanted a test could get one, including many people with symptoms.
As a result, a death rate for the coronavirus based on a percentage of those who tested positive amounts to a “fallacy,” Pandori said.
Most people with the virus experience fever and cough for up to three weeks. Older adults and people with existing health problems can face severe illness, including pneumonia and death. The vast majority recover.
Of more than 6,600 Nevadans who have tested positive for the coronavirus, state health officials reported Friday that 339 have died, or 5.5%.
However, antibody tests conducted around the country suggest the fatality rate could be much lower.
A Los Angeles County antibody study suggested 40 times more people were infected than detected, lowering the estimated fatality rate to less than 0.2%. In New York City, antibody tests indicated that as many as one in five people had been infected, suggesting a fatality rate of 0.5%.
For its antibody studies, the Reno lab is using an Abbott Laboratories test with a 99.6% accuracy rate.
The test is one of a dozen authorized by the U.S. Food and Drug Administration, but the agency warned in recent days that more than 100 additional tests of varying quality have flooded the market in the past two months without having undergone review.
In Las Vegas, the Southern Nevada Health District is ramping up plans for antibody tests by early June, said Dr. Fermin Leguen, acting chief health officer. Tests could be offered to the public and to high-risk populations such as the homeless and people in nursing homes.
Early antibody testing in and around Las Vegas got off to a bumpy start, with state health officials temporarily shutting down a pair of drive-thru testing operations over regulatory issues.
Private labs such as Quest and LabCorp have been providing antibody tests ordered by health care providers.
The University of Nevada, Las Vegas School of Medicine’s clinical program expects to start public antibody testing this month. It is still evaluating whether to use drawn blood or finger prick tests, said Dr. Michael Gardner, medical school vice dean of clinical affairs.
Testing “will help people feel more comfortable about getting business open, getting people back to work, those kinds of things,” Gardner said.
Health officials in the U.S. and around the world say tests could help identify people who had the virus, with or without getting sick. Researchers haven’t determined whether antibodies shield a person from becoming sick in the future.
“There’s some data and good reasons to think there’s going to be some level of immunity,” Gardner told the Review-Journal. “Maybe it’s just for a few years, or maybe, if you get it a second time, you won’t get it as severely.”
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