The Australian Immunisation Handbook 10th Edition 2013

• Table 2.1.6 can be used to assess the number of doses a child should have
received if they were on schedule. Check under the current age of the child
to see how many doses they should have already received and use that
number of doses as the starting point for calculating a catch-up schedule.
For example, a child who is 18 months old now should have received
3 doses of DTPa, 3 doses of IPV, etc.
• Table 2.1.7 lists the minimum acceptable interval between doses under special
circumstances, such as catch-up vaccination. Vaccine doses should not be
administered at less than the acceptable minimum interval. 16 In the majority
of instances, doses administered earlier than the minimum acceptable
interval should not be considered as valid doses and should be repeated,
as appropriate, using Table 2.1.6.
• Tables 2.1.8 to 2.1.11 are for calculating catch-up for Haemophilus influenzae
type b (Hib) and pneumococcal vaccination of children.
• Table 2.1.12 can be used to calculate a catch-up schedule for persons
aged ≥10 years.
In addition, the following principles should generally be applied when planning
catch-up vaccination:
• When commencing the catch-up schedule, the standard scheduled interval
between doses may be reduced or extended, and the numbers of doses
required may reduce with age. For example, from 15 months of age, only
1 dose of (any) Hib vaccine is required.
• As a child gets older, the recommended number of vaccine doses may change
(or even be omitted from the schedule), as the child becomes less vulnerable
to specific diseases.
• For incomplete or overdue vaccinations, build on the previous documented
doses. In almost every circumstance, it is advisable to not start the schedule
again, regardless of the interval since the last dose, but to count previous
doses. One exception to this rule is for oral cholera vaccine (see 4.1 Cholera).
• If more than one vaccine is overdue, 1 dose of each due or overdue vaccine
should be given at the first catch-up visit. Further required doses should be
scheduled after the appropriate minimum interval (see Table 2.1.7).
• A catch-up schedule may require multiple vaccinations at a visit. Give all the
due vaccines at the same visit – do not defer. See 2.2.9 Administering multiple
vaccine injections at the same visit.
• The standard intervals and ages recommended in the NIP schedule should be
used once the child or adult is up to date with the schedule.
• Some persons will require further doses of antigens that are available only
in combination vaccines. In general, the use of the combination vaccine(s)
is acceptable, even if this means the number of doses of another antigen
administered exceeds the required number.
42 The Australian Immunisation Handbook 10th edition