Please note!

This fact brief was originally published as an experiment to test the concepts behind fact briefs.

Readers should be aware that while there is still a lot of useful information in fact briefs like this one, not all of them reflect Gigafact's current methods and standards for fact briefs. If you come across any that you feel are out of date, don't hesitate to contact us at support@gigafact.org.

FACT BRIEF

Does the US have definitive numbers of how many unvaccinated people have natural COVID-19 antibodies?

Tuesday, May 18, 2021

By Lisa Freedland

Copy link

Copy featured image

There is no precise tally of how many unvaccinated Americans may carry natural COVID-19 antibodies acquired through exposure to the virus.

The Red Cross has tested 3.3 million unvaccinated blood donors for COVID-19 antibodies. Between June 2020 and March 2021, 7.5% of all those sampled had antibodies present; in the first week of March 2021, the figure was 20%, as the figure has risen over time. Blood donors are not a random sample of unvaccinated Americans, the report notes.

The Centers for Disease Control and Prevention estimates that about one-third of Americans have been infected. Natural immunity is expected to last about eight months after infection, but varies among individuals.

COVID-19 cases are thought to be underreported, and scientists don't know for certain how antibodies protect against variants, but early research looks promising.

This fact brief is responsive to conversations such as this one.

Sources

CNN COVID-19 antibodies present in about 1 in 5 blood donations from unvaccinated people

US Centers for Disease Control COVID-19 disease burden

National Institutes of Health Lasting immunity found after recovery from COVID-19

JAMA Network Estimation of US coronavirus infections, symptomatic infections, hospitalizations and deaths

Scientific American Your immune system evolves to fight coronavirus variants

ABOUT THE CONTRIBUTOR

Gigafact

Between 2020 and 2022, under close editorial supervision, Gigafact contracted a group of freelance writers and editors to test the concepts for fact briefs and provide inputs to our software development process. We call this effort Gigafact Foundry. Over the course of these two years, Gigafact Foundry writers published over 1500 fact briefs in response to claims they found online. Their important work forms the basis of Gigafact formats and editorial guidelines, and is available to the public on Gigafact.org. Readers should be aware that while there is still a lot of relevant information to be found, not all fact briefs produced by Gigafact Foundry reflect Gigafact's current methods and standards for fact briefs. If you come across any that you feel are out of date and need to be looked at with fresh eyes, don't hesitate to contact us at support@gigafact.org.

FACT BRIEF BY

Latest fact briefs

About fact briefs published on Gigafact

Fact briefs are short, credibly sourced summaries that offer “yes/no” answers in response to claims found online. They rely on publicly available, often primary source data and documents. Fact briefs are created by contributors to Gigafact —a nonprofit project looking to expand participation in fact-checking and protect the democratic process. See all fact briefs here.