When a vaccination is missed — the standard schedule and the principles of catch-up immunisation
Missing a dose does not mean starting over. The doses already given still count, and each vaccine has a defined minimum interval before the next one.
Missing a point on the immunisation schedule usually prompts the same worry: does the child have to start again? The short answer is that you do not start over. Doses already given still count, and the remaining doses are simply continued while observing the minimum intervals. This is known as catch-up immunisation.
The standard schedule marks the best timing
The national immunisation schedule is designed so that immunity is built just before the age at which a child's risk of that disease rises. Following it is therefore ideal. But the schedule is a recommendation, not a deadline.
Postponed because of a cold or a stomach bug, missed because of travel or a house move — in every case you simply continue. A late dose does not invalidate the earlier ones.
What matters is the minimum interval
Where a vaccine is given in several doses, a minimum interval must be kept between them. Giving a dose sooner than that interval may not produce sufficient immunity, and the dose may not be counted.
The reverse causes no problem: a longer gap is not an issue. Even six months behind, the next dose simply follows. Knowing this one principle removes most of the unnecessary worry.
Check the record first
Knowing exactly how far along the child is, is the starting point. The history can be checked on the immunisation helper portal or in the child's health booklet, and public health centres and paediatric clinics can look it up as well. If the child has been seen at several clinics, the consolidated record is the more reliable source.
If any doses were given abroad, bring the certificate. It must state the vaccine type and the date to be recognised.
Before nursery and before primary school
Immunisation status is checked at nursery admission and at primary school entry. An incomplete record does not lead to a place being refused, but the health centre or the school will follow up with guidance. Checking a few months ahead leaves time to sort it out calmly.
Before primary school in particular, the booster doses given between ages four and six cluster together. Once a child passes four, a review is worthwhile.
When a dose is postponed
- During an acute illness with a fever of 38 degrees or above
- Where a previous dose caused a severe allergic reaction (that vaccine)
- During immunosuppressive treatment (live vaccines)
A mild runny nose or slight temperature is often not a reason to postpone. The decision belongs to the doctor at the appointment. Even where a dose is deferred, it simply resumes after recovery.
What to watch for afterwards
Swelling at the injection site and a mild fever are common reactions and usually settle within a day or two. However, a persistent high fever, severe swelling at the site, or a child who is listless and not feeding warrants medical review.
Waiting at the clinic for 20 to 30 minutes after the injection is the rule. Immediate allergic reactions almost always appear within that window.
What to bring
The health booklet, identification and any previous records are enough. On the day, check that the child is generally well; if there is a fever, postponing is the better call. Afterwards, offer plenty of fluids and skip bathing and vigorous activity for the rest of the day.
Do not rub the injection site. If it swells, briefly holding a cool cloth against it is the right level of care.
Simultaneous doses are not something to fear
Parents often split vaccines across visits, assuming several on one day will be hard on the child. But every extra visit pushes the schedule further back, and a delayed schedule is harder to catch up. Giving vaccines at the same visit is an established practice and does not increase side effects.
If your child has had a particularly difficult time before, say so at the appointment. The combination can be adjusted.
Keep the records in one place
Records scatter easily when clinics change or the family moves. The consolidated history is held on the immunisation helper portal, so checking it periodically helps. Keep the paper booklet as well, and photograph it in case it is lost.
The moments when proof is needed — a nursery submission, a move abroad — arrive without warning. Organising it in advance saves a search later.
Frequently asked questions
Q. We are months behind. Does it all start again?
No. Doses already given are counted. The remaining doses continue, observing the minimum intervals.
Q. Can several vaccines be given on the same day?
In most cases yes, and it helps catch up by reducing the number of visits. Ask at the appointment which combinations are suitable.
Q. What does it cost?
Vaccines in the national immunisation programme are free at designated providers. A late dose is still supported provided the age criteria are met. Past the age limit it may become chargeable, so check first.
Related reading
This is an English translation of an article originally written in Korean. 한국어 원문 보기 ›