How many people are infected with the coronavirus? A major study will attempt to provide an answer.

The Centers for Disease Control and Prevention is embarking on an expansive study of the prevalence of novel coronavirus antibodies in people in 25 metropolitan areas, an effort to provide long-awaited insight into the way the virus is spreading and its presence in communities.

The study, which plans to test 325,000 people by fall 2021, will build on an antibody study that has been underway in six of those cities since March, according to Michael Busch, who is overseeing the study and is director of the Vitalant Research Institute. CDC spokeswoman Kristen Nordlund confirmed plans to announce the study but declined to discuss details.

Starting in June, this vast new antibody study will test samples from 1,000 blood donors each month for 12 months in the 25 metro areas. Researchers will test the samples for evidence of coronavirus antibodies, which are created by the immune system when someone is infected with the virus. Continue reading.