Daw gohebiaeth gan fyrddau iechyd lleol ac mae'r brechlyn am ddim drwy'r GIG. Gofynnir i bobl fod yn effro i sgamiau yn gofyn am arian neu wybodaeth bersonol.
Correspondence will come from local health boards and the vaccine is free of charge through the NHS. People are warned to be alert to scams asking for money or personal information.