DPT
3 letters
Historical clue formulations
- Childhood vaccine combo — 2022-11-04
- Vaccine letters — 2015-10-16
- Common combo vaccine — 2015-01-31
- Vaccine combo — 2014-07-10
- Vaccine combo — 2010-10-22
- Immunization letters — 1999-02-27
- Child's shot — 1994-01-26
