About this survey
CDC is partnering with commercial laboratories to conduct and publish results from a large-scale geographic seroprevalence survey that has tested de-identified clinical blood specimens from people in Connecticut, Louisiana, Minnesota, Missouri, the New York City metro area (Manhattan, Bronx, Queens, Kings, and Nassau), the Philadelphia metro area (Bucks, Chester, Cumberland, Delaware, Lancaster, Montgomery, Philadelphia), the San Francisco Bay Area (Marin, Contra Costa, Alameda, Santa Clara, San Mateo, and San Francisco), South Florida (Miami-Dade, Broward, Palm Beach, and Martin), Utah, and the Western Washington Region (King, Snohomish, Pierce, Kitsap, and Grays Harbor) for antibodies for the virus that causes COVID-19.
The survey includes people who had blood specimens tested for reasons unrelated to COVID-19, such as for a routine or sick visit during which blood was collected and tested by commercial laboratories in participating areas from each of the 10 sites. CDC aims to test about 1,800 samples collected from each of these 10 areas, approximately every 3–4 weeks. The results of these subsequent analyses are available on our interactive website and will be updated as samples continue to be analyzed. Researchers are looking to see what percentage of people tested already have antibodies against SARS-CoV-2, and how that percentage changes over time in each area.
More on the methodology used in this study is available online, Seroprevalence of Antibodies to SARS-CoV-2 in 10 Sites in the United States, March 23-May 12, 2020external icon.