, according to a new estimate.
The findings came from an analysis of blood donations. The Centers for Disease Control and Prevention analyzed donor blood from 143,000 people every 3 months during 2022, looking for the presence of COVID antibodies that meant a person had previously been infected with the virus. The prevalence of antibodies from previous infections steadily rose throughout the year. Antibodies from prior infection were found in 49% of donors as of Feb. 15, 2022, 59% of donors as of May 15, 2022, 70% of donors as of Aug. 15, 2022, and 78% of donors as of Nov. 15, 2022.
Donor blood also was analyzed for the presence of antibodies known to come from COVID vaccination. When the vaccine-induced and infection-induced antibody data were combined, the CDC estimated that 97% of people had antibodies as of the end of the 2022.
In the report, CDC authors explained that while the presence of antibodies is related to protection from infection and to less severe disease, the level of antibodies that a person has can vary. The authors said that no standards have yet been set that show a minimum level of antibodies needed to provide protection.
As of July 3, more than 1.1 million people had died in the United States from COVID-19, according to CDC data. Deaths for the first half of 2023 are down dramatically, compared with the first 3 years of the pandemic, with just 41,538 death certificates this year listing the virus as an underlying or contributing cause. About two in three COVID deaths this year occurred in a hospital or nursing home, and 89% of people who died from the virus this year have been age 65 or older.
A version of this article first appeared on WebMD.com.