Antibody tests have several important public health applications. High-quality serologic tests (e.g. the blood draw kind) can be used to estimate the prevalence of past viral infection or estimate the cumulative incidence of infection in a population (progress toward herd immunity).
They can help identify people that can be plasma donors. Plasma from donors with a good IgG titer can provide antibodies for infected persons that helps with their recovery. Antibody status can also help inform persons and employers who is at less risk for infection.
Last week APHL issued a document outlining potential public health applications for antibody testing. The statement provides an overview of serologic methods, considerations for selecting assays for seroprevalence surveys and test result interpretation, and outstanding research needs.
