Diphtheria, tetanus, & acellular pertussis vaccine (DTaP): when it's given
The routine schedule
These are the doses the CDC recommends for all children. Your paediatrician works from the same schedule and will tell you what your child is due.
| 2 mos | 1st dose |
| 4 mos | 2nd dose |
| 6 mos | 3rd dose |
| 15 mos–18 mos | 4th dose |
| 4-6 yrs | 5th dose |
What it protects against
- Diphtheria — what it is, how it spreads and what it does, summarised from NIH MedlinePlus.
- Tetanus — what it is, how it spreads and what it does, summarised from NIH MedlinePlus.
- Whooping cough (pertussis) — what it is, how it spreads and what it does, summarised from NIH MedlinePlus.
If your child is behind
Missing a dose is common and is almost always fixable — the schedule has a catch-up path built into it. Nothing has to start over. Bring it up at the next appointment.
Show the evidence
Source: CDC Child & Adolescent Immunization Schedule, 2025, a public-domain US Government work. See the schedule on cdc.gov.
We reproduce CDC's own wording for each dose, including where it says "See Notes", rather than paraphrasing. Doses are separated into routine and situation-dependent exactly as the published schedule separates them.
Educational reference, not medical advice. Your child's own schedule comes from their paediatrician and immunisation record, which account for their health, their history, and any doses already given.