Penn Medicine and the Mayo Clinic are working on tests that detect prior exposure COVID-19.

Penn Medicine and the Mayo Clinic are working on tests that detect past exposure to the novel coronavirus in frontline healthcare workers, even if they haven't had symptoms of the disease. The projects use "serology screening," or tests that detect antibodies in blood, to measure if people have been exposed to the virus at some point in the past — even in the absence of symptoms. Widespread serology testing essentially has the potential to figure out who's likely immune to the virus and let people return to work. Healthcare workers with antibodies could go back to the front lines with less worry about being infected. And government officials could obtain needed data on the spread of the disease in communities, helping them make tough decisions about lockdowns and other measures to curb the spread of the coronavirus. "These antibody tests are very important in figuring out when society can basically come back together," Scott Hensley, an associate professor of microbiology at the University of Pennsylvania, said in an interview. "Once enough of our population has antibodies against the virus, then eventually it will sort of run out of hosts to infect," he said. Serology tests are the next frontier of coronavirus screening, as individuals clamor for clarity on when lockdowns will end, doctors seek plasma donors for infected patients, and scientists need tools to check if incoming vaccines actually work, according to research published Monday by SVB Leerink. The antibody tests are different from tests that determine if you're currently sick with the coronavirus. Those tests look for the virus' genetic material in saliva or mucus. Scott Gottlieb, a former commissioner of the US Food and Drug Administration, said every major US region should undergo serologic testing, in a recent call with analysts at the investment bank Cowen's Washington Research Group, according to a published summary. He said the information could inform the handling of present and future lockdowns based on the "herd immunity" of a given community.

Supported with funds from the Philadelphia 76ers and Philadelphia Eagles, Penn Medicine's research spans from vaccine development to plasma transfers, using serology tests in many cases. Mayo Clinic Laboratories has been working around the clock to develop a serology test that launched Monday, according to Ginger Plumbo, a communications manager. "Although work is still ongoing to determine the level and duration of immunity in previously infected individuals, this sort of testing may be used, alongside other factors, to help guide the redeployment of healthcare workers, to screen potential plasma donors, potentially to evaluate the performance of vaccine candidates, and eventually to identify the true infection rate of SARS-CoV-2," she said in a statement to Business Insider.

Keeping tabs on healthcare workers One of Penn Medicine's new studies builds on technology developed by Mount Sinai and, once approved, aims to screen up to 1,000 frontline healthcare workers in the coming days. They'll give blood every 2 weeks, and the antibody tests will deliver quantitative results within 24 hours, according to Hensley. If someone's antibody count increases over time, researchers will suggest taking a coronavirus test to determine if the worker has an active infection, according to Hensley. If antibodies register, but don't increase, they were probably exposed to the virus a while ago. "If we're successful, we'll identify people that didn't even know they were actively exposed, so that we can take the proper steps to get them out of the healthcare system until they recover," Hensley said. "Another major goal is to measure how prevalent exposure is to healthcare workers," he continued. "Even with all the proper PPE and everything else, we don't really have a good idea about how much exposure is going on." The Mayo Clinic's test will also remain in-house for now. They'd like to increase capacity beyond healthcare workers in the practice, but can't for the foreseeable future due to the severe shortage of reagents, or the chemicals needed to run the test, according to Plumbo.