John Bessler, husband of U.S. Sen. Amy Klobuchar, has recovered from his serious bout with COVID-19, the disease caused by the new coronavirus (SARS-CoV-2) and is now helping Mayo Clinic research if antibodies from his blood can help fight the disease. 

Mayo Clinic posted video fo Bessler donating plasma. He told WCCO-TV that he's feeling better after being hospitalized in March as the virus caused him to get pneumonia and dropped his oxygen to a dangerous level. 

"My husband John has now recovered from Coronavirus and donated plasma this week at Mayo Clinic. Doctors hope the plasma will help others fight the virus. He is our superhero!" tweeted Sen. Klobuchar. 

Bessler, a professor at the University of Baltimore, started feeling sick when he was in Washington D.C. He initially thought he had a cold before his conditions worsened to the point he started coughing up blood. 

He wound up in the hospital with and was given oxygen. He was not placed on a ventilator. 

Bessler donated plasma through the Expanded Access Program for Convalescent Plasma, a national initiative aiming to collect plasma and its antibodies from recovered COVID-19 patients because those antibodies may help fight the disease. 

Here's more on how it works, according to the Mayo Clinic: 

"It turns out that for some other diseases caused by viruses, giving people the liquid portion of blood (plasma), obtained from those who have recovered from the virus, leads to more rapid improvement of the disease. Patients with COVID-19 may improve faster if they receive plasma from those who have recovered from COVID-19, because it may have the ability to fight the virus that causes COVID-19.

"Initial data available from studies using COVID-19 convalescent plasma for the treatment of individuals with severe or life-threatening disease indicate that a single dose of 200 mL showed benefit for some patients, leading to improvement.

"COVID-19 convalescent plasma has not yet been demonstrated to provide clinical benefit in patients affected by this disease. It's not known if this treatment will or will not help those with COVID-19 or if it will have any harmful effects, but this is one of the only treatments that we have at present."

In Minnesota, COVID-19 has been confirmed in 3,602 patients, 272 of whom have died. More than 1,600 patients, however, have recovered.