No, self-declaration is not accepted as proof of immunity

For measles, acceptable evidence of immunity is: (i) documented proof of completion of a course of vaccination involving 2 doses of a measles (or measles-containing) vaccine given at least 4 weeks apart; (ii) serological evidence of immunity; or (iii) laboratory confirmation of past infection.

For diphtheria, acceptable evidence of immunity is documented proof of vaccination with tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (“Tdap”) or tetanus and diphtheria toxoids (“Td”) which (1) reflects vaccination on or after 3 January 2012, and (2) is not expired. Documented proof of vaccination is regarded as expired after 10 years from the date of vaccination with a dose of Tdap or Td.