LOS ANGELES (CN) — As public health departments across the nation conduct testing for novel coronavirus, they’ve also begun testing individuals for antibodies — a move experts say could help officials determine how to redeploy the U.S. workforce and aid development of a vaccine.
The number of positive coronavirus cases in the U.S. eclipsed 662,000 Friday and nearly 30,000 Americans have died, according to Johns Hopkins University data. Meanwhile, the Trump administration continues its push for a summer reopening of the economy.
An economic recovery would benefit some of the more nearly 27 million Americans out of work and struggling in an economy expected to contract 6% this year, according to an International Monetary Fund report which also predicts the global economy will shrink 3%.
But U.S. health officials and political leaders, including California Governor Gavin Newsom, said this week any phased reopening of the economy must be guided by science and an understanding that a poorly planned restart could trigger mass infections.
Los Angeles County Public Health Department chief science officer Paul Simon told Courthouse News recovery plans must include safety measures to ensure workers won’t contract SARS-CoV-2 — the novel coronavirus that causes Covid-19 — or become infected again.
“We want to loosen things up as soon as possible, but we want to be careful because we could get another wave of infections that overwhelm hospitals,” Simon said, adding social-distancing measures stem potential case surges and give scientists time to develop a vaccine.
To better understand how the virus spread and how patients overcame infection, LA County partnered with University of Southern California researchers to look for antibodies in blood samples of 1,100 residents.
The serological test looks for immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies, proteins that help people fight off viral infections, Simon said.
“We think the study will give us a more complete picture of what the pandemic looks like,” Simon said regarding the serological test. “We’ve been primarily focused on people who’ve tested positive. What’s missing is people with mild symptoms or no symptoms who didn't seek testing.”
Results from the roughly 900 samples collected last week will shed light on residents’ risk of hospitalization and the county’s true fatality rate, which Simon believes will be lower as more data comes in.
“We're currently counting people that had Covid-19 and died, but the number of folks infected countywide is larger,” Simon said.
Simon said the test isn’t recommended for individual patient care since someone could have antibodies in their blood that cross-react with the testing kit.
Though the study targets a range of individuals across racial, economic and geographic differences, Simon said the study materials have not yet been translated into Spanish or other languages prevalent in the county.
Researchers plan to conduct a survey every three weeks with different sample groups in LA County, where 10,900 people have contracted the virus and 455 have died as of Thursday.
Los Angeles Mayor Eric Garcetti said in a public briefing Wednesday the serological testing will aid real-time identification of new Covid-19 cases as well as track hotspots where infections spike.
“These blood tests are the easiest way to see who has had the virus, but the test doesn’t speak to someone’s infectiousness,” Garcetti said, adding officials hope to make serological testing available on a mass scale.
This month, San Miguel County, Colorado, tested 986 people for antibodies, finding eight positive cases and 23 with “indeterminate” or borderline results.
Positive and borderline cases signal recent exposure and that someone is in the early stage of developing antibodies, officials said in a statement. They said the results are also treated as presumptively active infections.