Blood contains red blood cells, white blood cells, platelets, and plasma. Plasma is the liquid portion of blood that remains after the platelets and red and white blood cells are removed.
Plasma is 90 percent water, but it also contains immune system proteins and antibodies. This includes the antibodies your body makes when it learns to fight a virus like COVID-19.
You need plasma to clot blood, fight infections, heal wounds, and more. Plasma transfusions are used during surgeries and medical treatments. They can help people with chronic diseases as well as those with burns, shock, or trauma.
During the pandemic, blood donation centers were collecting plasma from people who had recovered from COVID-19 or who had received the vaccine within the last 6 months. This blood was used for what’s called a convalescent blood transfusion.
This type of transfusion uses the immune system proteins, or antibodies, from someone whose body has already fought an infection to help someone currently battling that same infection. Transfusions from vaccinated people who meet certain conditions can also be used.
Now that vaccinations and improved treatments for COVID-19 are available, the Red Cross and other organizations are no longer seeking plasma for convalescent transfusions. However, vaccinated people are eligible to donate plasma.
Most blood donation centers only require that vaccinated people are symptom-free on the day of their donation. You can read more about plasma donation here.