Some 96.4 percent of people aged 16 and older who donated blood had evidence of antibodies against COVID-19, researchers found. Samples of the blood were analyzed between July and September 2022.
The percentage of people with antibodies was up from 93.5 percent during January to March 2022 and from 68.4 in mid-2021.
People had antibodies from prior infection, vaccination, or both.
About 26 percent of people had antibodies from vaccination only, 22.6 percent had antibodies from infection only, and 47.7 percent had antibodies from both, the researchers found.