A Surprising Amount Of Unvaccinated Blood Donors Already Had COVID Antibodies

The American Red Cross tests all blood donations for COVID-19 antibodies, and the organization shared some interesting information about blood donations tested between June 2020 and March 2021 with CNN

They tested blood donations from over 3.3 million people from 44 different states who have not yet received a COVID-19 vaccination. Approximately 7.5 percent of those donations, overall, tested positive for antibodies. That doesn't mean that these people are immune to COVID-19 or that they are currently infected, but they likely had COVID-19 at some point. 

The number of people with COVID-19 antibodies has increased over time. In the first week of July 2020, only about 1.5 percent of blood donations contained antibodies. That number has been increasing exponentially, with more than 4 percent testing positive for antibodies in the first week of October 2020, then 12 percent the first week of January 2021, and about 20 percent in the first week of March 2021.

What do those antibodies mean? Will they protect people from getting COVID-19?

Will COVID-19 antibodies protect people from getting the virus?

Dr. William Schaffner, a CDC adviser on vaccines, shared some information with CNN about the antibodies found in blood donations. It shows that a large portion of the United States have been infected with COVID-19 at some point, whether they knew it or not — and this is not unheard of, as some people experience COVID-19 with no symptoms, also known as being asymptomatic. 

Antibodies aren't thought to be as reliable as a vaccination because scientists don't know yet if the naturally-occurring COVID-19 antibodies are effective against preventing the virus — or how long they might be effective. Dr. Schaffner points out that at least 80 percent of the United States population needs to be vaccinated against the virus to be effective for herd immunity. Herd immunity makes it difficult for the virus to spread throughout a population, protecting almost everyone, according to the CDC

Even if the antibodies were proven to protect people against getting COVID-19, there aren't near enough people to bring about herd immunity. You still need to get fully vaccinated, whether that's with a Moderna vaccination, Pfizer vaccination, or Johnson & Johnson vaccination. 

If you still want to know if you have COVID-19 antibodies, you can make a blood donation to the American Red Cross. They'll give you an account that will let you know if you have the antibodies because you may have had the virus without knowing it. If you do test positive, you can donate your plasma to help COVID-19 patients.