Convalescent plasma (kon-vuh-LES-unt PLAZ-muh) therapy uses blood from people who've recovered from an illness to help others recover.

The U.S. Food and Drug Administration (FDA) has given emergency authorization for convalescent plasma therapy with high antibody levels to treat COVID-19. It may be used for some hospitalized people ill with COVID-19 who are either early in their illness or who have weakened immune systems.

Blood donated by people who've recovered from COVID-19 has antibodies to the virus that causes it. The donated blood is processed to remove blood cells, leaving behind liquid (plasma) and antibodies. These can be given to people with COVID-19 to boost their ability to fight the virus.

Convalescent plasma therapy may be given to people with COVID-19 who are in the hospital and are early in their illness or have a weakened immune system.

Convalescent plasma therapy may help people recover from COVID-19. It may lessen the severity or shorten the length of the disease.

Blood has been used to treat many other conditions. It's usually very safe. The risk of getting COVID-19 from convalescent plasma hasn't been tested yet. But researchers believe that the risk is low because donors have fully recovered from the infection.

Convalescent plasma therapy has some risks, such as:

• Allergic reactions
• Lung damage and difficulty breathing
• Infections such as HIV and hepatitis B and C

The risk of such infections is low. Donated blood must be tested for safety. Some people may have mild complications or none at all. Other people may have severe or life-threatening complications.

Your doctor may consider convalescent plasma therapy if you're in the hospital with COVID-19 and you are early in your illness or you have a weakened immune system. If you have questions about convalescent plasma therapy, ask your doctor.

Your doctor will order convalescent plasma that is compatible with your blood type from your hospital's local blood supplier.

Before the procedure

Before convalescent plasma therapy, your health care team prepares you for the procedure. A health care team member inserts a sterile single-use needle connected to a tube (intravenous, or IV, line) into a vein in one of your arms.

During the procedure

When the plasma arrives, the sterile plasma bag is attached to the tube and the plasma drips out of the bag and into the tube. It takes about 1 to 2 hours to complete the procedure.

After the procedure

You'll be closely monitored after you receive the convalescent plasma. Your doctor will record your response to the treatment. He or she may also record how long you need to stay in the hospital and if you need other therapies.

It's not yet known if convalescent plasma therapy will be an effective treatment for COVID-19. You might not experience any benefit. However, this therapy might help you recover from the disease.

Data from several clinical trials, studies and a national access program suggest that convalescent plasma with high antibody levels may lessen the severity or shorten the duration of COVID-19 in some people when given early in the disease or in those with weakened immune systems. However, more research is needed to determine if convalescent plasma therapy will be an effective treatment for COVID-19.