Guide
Catching up on vaccines at 16 to 18 years
A teen aged 16 to 18 with no prior vaccines needs about 12 doses over as few as 7 visits (12 visits at one dose per visit), against 26 doses on the on-time schedule.
Key takeaways
- Of the 26 on-time doses in these 8 vaccines, 12 are still needed at 16 to 18 years: IPV 3 instead of 4, Hib 0 instead of 4, PCV 0 instead of 4 and DTaP replaced by Tdap.
- From 16 to 18 years, 3 doses per visit takes 7 visits over 8 months, ending at 16 years 8 months; one dose per visit takes 12 visits over 13 months.
- Rotavirus is no longer possible: the final dose is due before 8 months and this child is 15 years 4 months past it.
- By 16 to 18 years, an on-time child would already have had 26 of these routine doses; this plan counts none of them as given.
Doses needed at 16 to 18 years, vaccine by vaccine
| Vaccine | On time | If started now | Planner minimum | Why |
|---|---|---|---|---|
| HepB (Hepatitis B) | 3 | 3 | 3 | No reduction. Gaps of 4 weeks and 8 weeks between doses. |
| DTaP (Diphtheria, Tetanus & Pertussis) | 5 | Tdap instead | Tdap instead | Age 7+: DTaP is replaced by Tdap catch-up — ask your child's healthcare practitioner. |
| IPV (Polio (Inactivated)) | 4 | 3 | 3 | 3-dose delayed path (3rd dose at age ≥4 is the final dose). |
| Hib (Haemophilus influenzae type b) | 4 | Not needed | 0 (not needed) | Healthy children no longer need it from age 5; this child is 11 years past that. |
| PCV (Pneumococcal Conjugate) | 4 | Not needed | 0 (not needed) | Healthy children no longer need it from age 5; this child is 11 years past that. |
| MMR (Measles, Mumps & Rubella) | 2 | 2 | 2 | No reduction. Second dose at least 4 weeks after the first. |
| VAR (Varicella (Chickenpox)) | 2 | 2 | 2 | No reduction. Second dose at least 3 months after the first. |
| HepA (Hepatitis A) | 2 | 2 | 2 | No reduction. The two doses are at least 6 months apart. |
"If started now" and "Planner minimum" agree at 16 to 18 years. A range such as 4–5 means the lower number applies when the final dose is given at age 4 or later.
Visits and finish age
Starting at 16 to 18 years, three doses per visit needs 5 visits fewer than one at a time and ends 5 months sooner. The required gaps set the floor: the earliest plan ends 8 months after the first visit, at 16 years 8 months.
| Pace | Visits | Doses placed | Last visit at |
|---|---|---|---|
| 1 dose per visit, 1 month apart | 12 | 12 | 17 years 1 month |
| 3 doses per visit, 1 month apart | 7 | 12 | 16 years 8 months |
| Planner preset: one vaccine per visit, 2 months apart | 12 | 12 | 17 years 10 months |
Pace figures come from the same engine as the planner, with a healthy child, the planner's default vaccines and no prior doses.
Rules that apply at 16 to 18 years
- Rotavirus (RV) is not possible: its final dose must come before 8 months, which this child passed 15 years 4 months ago.
- At 16 to 18 years, Hib and PCV are dropped: healthy children no longer need either from age 5, which takes 8 doses off the on-time total.
- At 16 to 18 years the planner's DTaP note applies: Age 7+: DTaP is replaced by Tdap catch-up — ask your child's healthcare practitioner.
- At 16 to 18 years, hepatitis A needs 6 months between its two doses, the longest fixed wait in the plan, so it often sets the finish.
Questions parents ask at this age
How many vaccines does a teen aged 16 to 18 need to catch up?
At 16 to 18 years the plan is 12 doses (HepB 3, DTaP Tdap, IPV 3, Hib 0, PCV 0, MMR 2, VAR 2, HepA 2) out of 26 on the on-time series, of which an on-time child has had 26 by now.
How many visits will a teen aged 16 to 18 need?
From 16 to 18 years: as few as 7 with up to 3 doses per visit (finishing at 16 years 8 months), 12 with one dose per visit and 1 month between (17 years 1 month), or 12 on the planner's one-vaccine-per-visit preset with 2 months between (17 years 10 months).
Is it too late to catch up at 16 to 18?
No. A series is never restarted and doses already given count. With nothing given, the plan is 12 doses, 7 visits at 3 doses per visit, and it can end at 16 years 8 months.
How soon can a 17-year-old be done?
The fixed minimums add up to about 8 months from the first visit, set by the 6 months hepatitis A gap. One vaccine per visit at the planner's 2-month spacing takes 22 months.
Build the plan for 16 to 18 years
Enter the birth date and any doses already given; the planner counts them and spaces the rest.
Open the planner in catch-up mode One vaccine per visit Up to 4 per visitSources
Primary sources only. Links open the publisher's own page.