Cars stood in line along a Long Island town's street on Wednesday, with those inside waiting for a prick of their finger — a simple blood test that could bring a little peace of mind.

Those who lined up in Franklin Square all had at least one thing in common: all had been diagnosed with and recovered from COVID-19. Now they were trying to see if surviving the virus had given them the antibodies that would make them immune to getting it again.

"I feel like I want to know if I have immunity," said Elmhurst pediatrician Wilfred Lao, who recovered from the coronavirus in March. After receiving the test, it showed that Lao did have the antibodies in his blood that could provide immunity.

There were multiple police officers and doctors coming to the testing site, hoping they could get the test that may be the key to restarting the country's economy.

"You can go back to work know you're safe, and safe to other people to," said Dr. Ramon Tallaj, whose Somos Health Network is offering 70,000 free blood antibody tests. Gov. Andrew Cuomo called such tests a priority for first responders and essential workers.

"The more testing, the more open the economy, but there's not enough national capacity," Cuomo said.

The Somos Health Network said it will be opening sites in the Bronx and Washington Heights later this week. The tests will also be free there, but those interested have to call ahead to make an appointment.

However, there is a big question mark surrounding these blood tests: they are not definitive. The Centers for Disease Control says there's no proof COVID-19 antibodies give you full immunity to the virus.

"Will it give immunity for a week? For a month? Nobody knows," said Dr. Jason Golbin, of Long Island Catholic Health Services. Golbin is organizing a trial of COVID antibodies at the six hospitals that make up Catholic Health Services, hoping more studies will provide answers. With any luck, soon antibodies can be taken from virus survivors and be used to treat other sick patients.

"I'm cautiously optimistic that this will help our patients," Golbin said.

Despite the possible issues with the test, former COVID patient Lao said that he would be going back to work.

"That's what we sign (up) for, and that's what we have to do," Lao said.