Your questions, answered
“How wise is it to donate blood after getting the vaccine while your body is building the immune response?” — Carl in Missouri
“If a vaccinated person donates blood or plasma, does vaccine get donated along with it?” — Julie in North Dakota
Good questions! We've had a few along these lines recently — you all are really thinking through possible consequences of vaccination. Here with answers is Lindsey Bever, who combed through Red Cross donation guidelines and spoke with Northwestern University infectious-disease expert Rob Murphy. She writes:
Waiting to donate blood isn't necessary.
Blood supplies took a hit during the pandemic, with the pause in blood drives and other cancellations. If you want to help fill up blood banks, you don’t need to wait to donate after being vaccinated. That's true for any of the three Food and Drug Administration-authorized versions (Pfizer, Moderna, Johnson & Johnson) of the vaccine, unless you are showing symptoms, per the Red Cross.
Those who have been vaccinated can also donate platelets. The organization is not accepting convalescent plasma from people who have taken a vaccine.
Blood donation won't weaken your post-vaccine protection. When someone has had the coronavirus or has received a vaccine to protect against it, the body’s immune system produces antibodies and protective T cells, white blood cells that help protect against the disease. Although those immune responses are stored throughout the body, Murphy said the amount that would be taken during blood donation would not be enough to matter.
Unlike with some diseases, coronavirus immunity does wane over time, but routine blood donation would not factor into that.
Positive effects of a vaccine won't transfer through donated blood.
Average adults have about 10 pints of blood in their bodies, and whole blood donation requires only about 1 pint. Murphy said the amount of coronavirus antibodies in that amount of blood would be negligible at best, not to mention the fact that the human body is constantly producing more blood.
“You’ll get their antibodies, but it’s not enough to make any kind of impact,” he explained.
Read more: Can you give blood after the coronavirus vaccine? What to know about post-donation immunity.