COVID-19 antibody tests are used to find out whether a person has antibodies from previously being infected with coronavirus or being vaccinated.
Nod profion COVID-19 yw canfod y bobl sydd wedi'u heintio gan y feirws ar hyn o bryd, drwy gynnal prawf swab, neu ganfod y bobl sydd wedi dod i gysylltiad â'r feirws, drwy gynnal prawf gwrthgyrff.