<prompt> Non immunized susceptible diphtheria contacts should receive:ErythromycinPenicillin and diphtheria antitoxinPenicillin, diphtheria antitoxin and DPT vaccineNo treatment is required  <response>: Non immunized contacts should receive prophylactic penicillin or erythromycin. They should also be given 1000 to 2000 units of antitoxin and actively immunized against diphtheria. Ref: Park 21st edition, page 151. 