Contents >> Health >> Risk Factors: Children's immunisation

Health Risk Factors: Children's immunisation

Although the overall proportion of young children fully immunised against the major infectious diseases has increased, the proportion of six year olds in 1989-90 who were fully immunised against whooping cough had decreased since 1983.

Immunisation programs for children are recognised as one of the most effective public health interventions. Infectious diseases such as diphtheria, whooping cough and polio are no longer major causes of death and disability in Australia due to mass immunisation programs.

Between 1983 and 1989-90, due to the introduction of a combined measles/mumps vaccination, there was a rise in the proportion of six year olds fully immunised against measles. However, during the same period there was a decline in the proportion fully immunised against whooping cough. Overall the proportion of six year olds fully immunised against diphtheria/tetanus, whooping cough, polio and measles rose from 55% in 1983 to 71% in 1989-90. The low level of full immunisation against all conditions in 1983 (6%) reflects the introduction of the mumps vaccine in 1983 and the consequent low proportion of six year olds fully immunised against mumps. In 1989-90, 69% of six year olds were fully immunised against all conditions.

Recently there has been concern over perceived low levels of immunisation against conditions such as whooping cough and measles in Australia. There have also been reported outbreaks of these diseases in some States. Reported cases of measles rose from 248 in 1988, when the disease was declared notifiable to 4,461 in 1993. In addition there were 153 cases of whooping cough in 1988 compared to 3,956 in 1993. However, deaths from these two conditions remain low with 18 deaths due to measles and 6 due to whooping cough in the period 1988-921.

Many parents may now have little understanding of the seriousness of paralytic poliomyelitis, diphtheria and whooping cough and this may have contributed to the difficulties in achieving maximum immunisation levels.

Children are potentially at risk of contracting the various infectious diseases throughout all their early years of life. A more complete picture of their immunisation status is therefore obtained by examining the entire 0-6 years age group. The comparison of the change in the rates of immunisation between 1983 and 1989-90 is based on the immunisation status of six year olds because comparable data for age 0-6 years are not available for 1983.

In 1989-90, 59% of children aged 0-6 years were fully immunised against all the conditions: diphtheria, tetanus, whooping cough, polio, measles and mumps, and 4% were not immunised against any conditions. The majority of these children were aged under six months. The proportions of children not immunised for any conditions decreased with age possibly indicating late immunisation against certain conditions. 38% of children aged 0-6 years were partly immunised against some conditions, mostly whooping cough and polio. The highest proportions of children partly immunised were aged one year.

67% of one year olds were fully immunised against measles in 1989-90 compared to 92% of two year olds. The low level of immunisation of one year olds reflects the later administration of the measles vaccine rather than a failure to immunise. Later immunisation for measles may be partly due to the low occurrence of fatal attacks of measles in Australia. There were a total of 45 registered deaths from measles between 1982 and 1992, with 9 of these being children aged 0-6 years1. There may also be some concern by parents about administering the vaccine to babies less than one year old.

SIX YEAR OLDS FULLY IMMUNISED
1983
1989-90
Disease
%
%
Diphtheria/tetanus
92.8
93.1
Whooping cough
93.1
85.1
Poliomyelitis
58.6
79.5
Measles
64.8
91.5
All above conditions
54.7
71.1
Mumps
13.7
87.2
All conditions
6.2
68.7
Source: Children's Immunisation Survey (1983); National Health Survey (1989-90)

CASES OF NOTIFIABLE DISEASES REPORTED
1988
1989
1990
1991
1992
1993p
Disease
no.
no.
no.
no.
no.
no.
Diphtheria
61
1
7
8
14
39
Measles
248
169
880
1 380
1,425
4,461
Whooping cough
153
614
862
337
739
3,956
Poliomyelitis
-
-
-
-
-
-
Tetanus
5
11
6
7
14
8
Source: Department of Health, Housing and Community Services Annual Report
Immunisation status
Immunisation status is defined in terms of the degree to which the recommended course of vaccination against a particular disease has been received. Children who have received all the vaccinations appropriate to their age are regarded as fully immunised, while those who have received only some of them are regarded as partly immunised. Full immunisation status does not necessarily imply complete immunity since in a small number of cases the vaccination may not take effect.
RECOMMENDED CHILDHOOD IMMUNISATION SCHEDULE
Age
Disease
2, 4 and 6 months
Diphtheria, tetanus, whooping cough, poliomyelitis
12-15 months
Measles, mumps
18 months
Diphtheria, tetanus
5 years
Diphtheria, tetanus, poliomyelitis
Source: National Health and Medical Research Council (1986) Immunisation Procedures

IMMUNISATION STATUS OF CHILDREN AGED 0-6 YEARS, 1989-90
Immunisation status
Less than 6 months
6 to less than 12 months
1 year
2-3 years
4-6 years
Total 0-6 years
%
%
%
%
%
%
Fully immunised
    Diphtheria/tetanus
43.3
95.3
96.8
95.0
92.3
90.4
    Whooping cough
42.9
67.3
89.7
66.9
81.0
74.2
    Poliomyelitis
37.7
63.2
81.9
87.3
77.7
76.9
    Measles
. .
. .
67.3
92.6
92.6
88.6
    Mumps
. .
. .
66.1
89.1
86.8
84.4
    All conditions
37.2
62.0
56.4
59.5
61.9
58.5
Partly immunised
    Diphtheria/tetanus
16.9
2.9*
1.6*
4.0
6.9
5.7
    Whooping cough
16.4
29.8
7.3
30.7
15.9
20.2
    Poliomyelitis
15.5
30.0
13.7
10.1
20.4
17.0
    Measles
. .
. .
. .
. .
. .
. .
    Mumps
. .
. .
. .
. .
. .
. .
    All conditions
23.0
36.1
42.2
39.6
37.5
37.5
Not immunised
    Diphtheria/tetanus
39.8
1.9*
1.6*
1.0*
0.8
3.9
    Whooping cough
40.7
2.9*
2.9
2.4
3.1
5.6
    Poliomyelitis
46.7
6.8
4.4
2.5
1.9
6.2
    Measles
. .
. .
32.7
7.4
7.4
11.4*
    Mumps
. .
. .
33.9
10.9
13.2
15.6
    All conditions
39.8
1.9
1.4
0.9
0.7
4.0
Source; National Health Survey


Immunisation and immigration
Children of Australian born mothers were more likely to be fully immunised than children of mothers born overseas. There was also an association between the time that overseas born mothers had lived in Australia and the immunisation status of their children.

Children whose mothers had arrived most recently in Australia had the lowest levels of full immunisation. One-third of children whose mothers had arrived in the previous five years were fully immunised in 1989-90 compared to half of children whose mothers had been in Australia for ten years or more. Children whose mothers had arrived in Australia within the last five years had particularly low rates of full immunisation against whooping cough and measles.

Some insight into differences between overseas born groups can be obtained by examining language spoken at home by the mother. Children of mothers who spoke only English at home had immunisation levels close to the children of Australian born mothers. However, in general, English speaking migrants have been in Australia longer than other migrants. Those children whose mothers spoke Greek or Chinese languages at home had the highest levels of full immunisation (64%-65%), while those children whose mothers spoke Vietnamese or other Asian languages (other than Chinese) had the lowest levels of full immunisation (36% and 26% respectively). Polio had a particularly low full immunisation rate (43%) among children whose mothers spoke Asian languages other than Vietnamese or Chinese.

FULLY IMMUNISED PROPORTION OF CHILDREN AGED 0-6 YEARS, 1989-90
Diphtheria/ tetanus
Whooping cough
Polio
Mumps(a)
Measles(a)
All conditions
Birthplace of mother
%
%
%
%
%
%
Australia
90.9
75.1
78.3
89.2
86.1
56.1
Overseas
88.9
71.5
72.4
87.5
79.5
52.1
    Arrived before 1980
91.5
75.5
75.4
89.8
85.6
50.4
    Arrived 1980-1984
88.4
72.5
70.2
88.0
79.0
42.7
    Arrived 1985-1990
82.5
60.1
66.8
81.2
63.1
32.3
Total
90.4
74.2
76.9
88.6
84.4
58.5
(a) Children aged 1-6 years.

Source: National Health Survey
International Comparison
The World Health Organisation estimated the number of fatal attacks of measles to be just under 900,000 world wide in 1990. Non-fatal attacks of measles can also have serious consequences and may be associated with subsequent malnutrition, pneumonia, diarrhoea, vitamin A loss, blindness and deafness.

Targets set for measles immunisation by UNICEF were 80% of one year olds immunised against measles by 1990 and 90% by the year 2000. In The Progress of Nations released by UNICEF in 1991, Australia was ranked 26th among industrialised nations in terms of measles immunisation of children aged one year old.

ONE YEAR OLDS FULLY IMMUNISED AGAINST MEASLES, 1991
Country
%
Country
%
Australia
68
Korea
96
Canada
85
Malaysia
79
China
95
New Zealand
90
France
69
PNG
52
Greece
76
Singapore
90
Hong Kong
42
Sweden
95
Indonesia
78
UK
89
Italy
50
USA
77
Japan
73
Vietnam
88
Source: UNICEF (1991) The Progress of Nations

FULLY IMMUNISED PROPORTION OF CHILDREN AGED 0-6 YEARS WITH OVERSEAS BORN MOTHERS, 1989-90
Diphtheria/ tetanus
Whooping cough
Polio
Mumps(a)
Measles(a)
All conditions
Language spoken at home (by mother)
%
%
%
%
%
%
English
90.4
73.6
76.2
88.6
80.3
54.5
Arabic (including Lebanese)
83.8
62.3
55.9
86.1
84.5
45.5
Chinese languages
90.4
79.0
81.3
92.5
75.5
65.0
Greek
90.6
79.3
71.6
100.0
100.0
63.7
Italian
87.2
69.6
56.5*
84.8
84.0
37.1*
Vietnamese
78.5
53.3*
67.5*
66.0*
66.0*
35.9*
Other Asian languages
70.6
51.8
42.7
81.2
62.6
26.1*
Other European languages
90.5
72.6
73.4
81.9
78.4
50.0
Other languages
89.9
66.7
68.7
87.0
68.2
43.0
Total
88.9
71.5
72.4
87.5
79.5
52.1
(a) Children age 1-6 years.

Source: National Health Survey


Endnotes
1 Causes of Death (3303.0).




Previous PageNext Page