The American Red Cross and other organizations that accept blood donations began routinely testing donors' blood for COVID-19 antibodies in June 2020. The tests are to determine whether donors may have been exposed to the virus that causes COVID-19.
However, the antibody tests are not diagnostic. A positive antibody test does not confirm infection by or immunity to COVID-19.
EDITORS' NOTE: The American Red Cross announced that as of June 15, 2020, all donors will have their blood tested for COVID-19 antibodies to determine whether they may have had previous exposure to the coronavirus. There is no charge for the testing, which is being conducted as a public service. The Red Cross emphasizes that this is not a diagnostic test for COVID-19 and does not confirm either infection or immunity. People who are feeling ill for any reason should not present themselves for blood donations. Other blood donation centers around the U.S., including OneBlood and Vitalant, have also announced they are testing donor samples for COVID-19 antibodies.
In early March 2020, as the availability and cost of testing members of the public for the COVID-19 coronavirus disease sweeping the globe was a hot issue, a widely-shared tweet offered a supposed "loophole" for obtaining such testing for free. Just volunteer to donate blood, it asserted, and the agency taking your donation would have to test you for free:
However, it was not the case at that time that all blood banks were performing coronavirus tests on donors — as news reports have noted, "blood donation centers do not have test kits on hand to check for the coronavirus."
Moreover, as the American Red Cross declared in a statement, conducting such tests on donors is unnecessary because "there is no data or evidence that COVID-19 can be transmitted by blood transfusion, and there have been no reported cases of transmissions for any respiratory virus, including this coronavirus, worldwide."
The Associated Press likewise reported of the subject that:
Blood banks said they do not test for the novel coronavirus as part of the donation process. [...]
“We do a whole range of testing on blood donations as required by the FDA, but screening or testing for coronavirus is not happening,” said Kate Fry, chief executive officer of America’s Blood Centers, a North American network of nonprofit blood centers. The network oversees more than 600 blood collection sites.
Dr. Pampee Young, chief medical officer of the American Red Cross, told the AP that screeners do not test for the coronavirus as part of the process.
“The last thing we would want is for people who are not healthy coming just to try to get tested,” she said.
However, organizations such as the American Red Cross do advise that people should not donate blood now if they know or suspect they have been exposed to the coronavirus:
[T]he American Red Cross has implemented new blood donation deferrals out of an abundance of caution. We are now asking that individuals postpone their donation for 28 days following:
o Travel to China and its special administrative regions, Hong Kong and Macau, as well as Iran, Italy and South Korea.
o Diagnosis of COVID-19, contact with a person who has the virus, or is suspected to have it.
The American Red Cross does advise that, "Right now, eligible and healthy donors are strongly urged to make an appointment to prevent shortages."
As noted at the top of this article, the American Red Cross and other blood donation centers began conducting routine COVID-19 antibody tests on donors' blood as a public service, but this is not the same as diagnostic testing and will not determine if an individual is infected with COVID-19.