Local hospitals are set to become among the first in the state to collect and use the plasma that experts say could help patients fight the coronavirus.

Nuvance Health, the network that operates Danbury, Norwalk and five other hospitals, is opening three centers where people who have recovered from the coronavirus may donate their plasma to be used to try to treat current patients.

These donations could be potentially “lifesaving,” the health network said, because the plasma has antibodies that may help patients battling the virus.

“These are antibodies the donor has produced to fight the infection when they had it,” said Dr. Paul Fiedler, laboratory director for Nuvance Health. “Now, they are transferring that capacity to the recipient of the transfusion.”

Danbury Hospital has treated 40 patients with plasma, while Norwalk has treated 35; New York hospitals Vassar Brothers and Putnam Hospital Center have treated 25 and three patients, respectively. Nuvance does not yet have data on how well plasma therapy has worked for the more than 100 patients systemwide who have been treated so far.

But this method has been effective in reducing the severity of symptoms for other viruses, Fiedler said.

“We’re optimistic that will hold true for this infection, as well, but it’s not been proven,” he said.

Norwalk Hospital’s center will open Wednesday, while Danbury Hospital’s will open on Friday, with Vassar Brothers Medical Center in Poughkeepsie, N.Y., launching on Monday.

Other hospitals around the state and country are using plasma to treat patients, but many in Connecticut get their plasma from the American Red Cross or blood centers in New York and Rhode Island.

This includes Stamford Hospital, which is conducting the state’s first clinical trial, and Yale New Haven and Greenwich hospitals, which are participating in a federal clinic led by Mayo Clinic, which has 1,978 sites and 4,524 patients nationwide.

Nuvance Health system had been using plasma from the New York Blood Center and the American Red Cross.

But the high demand led Nuvance to open its own centers, said Dr. James Nitzkorski, a surgical oncologist at Nuvance Health.

“Plasma contains antibodies that can fight infection,” he said in a statement. “When someone recovers from a COVID-19 infection, they do so, in part, because the antibodies can neutralize the virus and make someone better. That plasma is then taken from a donor, prepared and then given to a critically ill, COVID-19 patient.”

Nuvance still plans to use donations from New York Blood Center and Red Cross, as needed.

“They are a key part of the effort,” said Marcela Rojas, spokeswoman for Nuvance.

Two patients a day are able to donate plasma in Danbury, with four patients able to donate each day in Norwalk and Vassar Brothers, Fiedler said. Two to three patients may be helped through one donation, he said.

“We’re going to keep running this as long as it’s needed clinically,” Fiedler said.

Donors must have tested positive for the virus, but have since recovered. They either must be symptom-free for 14 days with a negative test, or be symptom-free for 28 days with no need for a negative test.

Donors must register online and will be contacted by staff. If donors are not feeling well or have low protein or hemoglobin concentration, they may not be eligible, Fiedler said.

So far, almost 1,460 people have registered to donate.

The centers are prioritizing donations from those who have been symptom-free for 28 days because doctors can be more confident that the patients do not have the virus, Fiedler said.

The donation process takes an hour or two, and donors must wear masks.

While some people become nauseous or vomit, side effects are usually minimal, Fiedler said.

Blood is collected into a machine that separates the plasma from the red blood cells and saline, he said. The red blood cells and saline are transfused back into the body, while 650 milliliters of plasma is collected, he said.

That plasma is split into three units, with one to two units given to patients with the virus through a one-time transfusion, Fiedler said.

The antibodies may start working quickly, he said.

“But that doesn’t mean we would see a clinical effect immediately,” Fiedler said.