Hawaii Pacific Health will begin coronavirus antibody testing for 7,200 employees to assess the level of infection in the health care workforce.

The parent company of Kapiolani Medical Center for Women & Children, Pali Momi Medical Center, Straub Medical Center and Wilcox Health on Kauai is the first in Hawaii to offer the antibody screenings at no cost to its workers through Clinical Labs of Hawaii, which began offering blood tests Thursday to detect immunoglobulin G, or IgG — which develops about two weeks after COVID-19 infection. The cost of the program is estimated at about $360,000.

“Antibody testing could be part of the solution to reopening Hawaii’s economy,” HPH President and CEO Ray Vara said in a news release. “We care deeply about this community. It is our home and we would like to help move us to a better place from a public health standpoint as well as economically.”

Antibody tests are used to detect the “disease-fighting proteins the body creates to neutralize the virus” in people who were infected but did not show symptoms or had mild illness. Clinical Labs will draw a blood sample for testing, with results available within 48 to 72 hours.

“Having results for a large group of employees will help us to know how many people had asymptomatic infection, how active the virus was in our community, and may help us to know how well all of our efforts are working as far as preventing infection,” said Dr. Melinda Ashton, HPH executive vice president and chief quality officer. “Although that won’t change anything about how we approach the use of PPE (personal protective equipment) for health care workers or wearing of masks in public, the aggregate results will help us contribute to what is known about how the COVID-19 virus has behaved in our community.”

The antibody test is not used to diagnose active infection. The current diagnostic tests — which involve inserting a long swab into the back of the nose to retrieve virus particles — detect the virus if it is actively multiplying in the body and is most effective in identifying acute or early infection, according to the World Health Organization.

“We haven’t seen any value in doing the (diagnostic) virus test on everybody because timing on that matters so much. We’d kind of have to do it on everybody every day to know what was going on with the virus, and we don’t have enough of (those tests),” Ashton said. “We know the peak amount of disease was several weeks ago. Now is a good time to go out and test (for antibodies). We know there’s been a lot of concern. Everybody’s curious about whether they’ve been exposed to the virus.”

Hawaii Pacific Health will establish sites next week at each of its locations to make it easier for employees to get their blood drawn and tested.

Participation is voluntary, though the company is encouraging all workers to get tested. Others in the community wanting to get an antibody test must get an order by a physician. The tests, authorized by the U.S. Food and Drug Administration for emergency use during the public health crisis, cost about $50. It is manufactured by Abbott, which has also developed a rapid test that can detect COVID-19 in minutes.

The presence of antibodies — proteins produced in the blood by the immune system to protect against viruses — generally means a person has immunity. But the Centers for Disease Control and Prevention has said people with coronavirus antibodies still could be infectious. It is also unclear whether the antibodies will protect people from getting reinfected by COVID-19 or whether enough people will have the antibodies to make opening the economy safe.

“Does that mean that you can’t get infected again? Does that mean you can’t carry the virus in your nose? We don’t know those things, actually, so we need our employees to still follow all the same policies, procedures and rules that have made it possible for us to reduce the amount of virus in Hawaii,” Ashton said. “Everything that we did — all the social distancing, all the stay at home, all the mask-wearing — has made a big difference. Having a blood test doesn’t change that.”

Participants will get the results of their antibody tests, but any research will be based on aggregate data and not individual results in complying with privacy laws.

The state is considering ways to safely reopen for business as pressure mounts following a steady drop in coronavirus cases in recent weeks. Hawaii’s tally of coronavirus cases climbed by five to 618 on Thursday, with the state’s COVID-19 death toll at 16. A total of 526 patients have recovered since the start of the outbreak — more than 85% of those infected in the islands. Of the 30,396 coronavirus tests conducted by state and clinical laboratories, 2% have been positive — a consistent drop over the past couple of weeks.

Gov. David Ige announced this week that the state will slowly begin to reopen in phases, generally starting today with a limited number of businesses, as residents in lockdown struggle to make ends meet. In the absence of a vaccine, which stimulates antibodies to protect people against infection, knowing how many people might already have some level of immunity is helpful, Ashton said.

“All indications are that in Hawaii we didn’t have as much of the COVID-19 virus circulating widely as they did in New York, for example. As we begin to open up again, it will be useful to know … do we have very little protection among us in the community or a lot of protection?”