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 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 | | | | | | |
| 43.3 | 95.3 | 96.8 | 95.0 | 92.3 | 90.4 |
| 42.9 | 67.3 | 89.7 | 66.9 | 81.0 | 74.2 |
| 37.7 | 63.2 | 81.9 | 87.3 | 77.7 | 76.9 |
| . . | . . | 67.3 | 92.6 | 92.6 | 88.6 |
| . . | . . | 66.1 | 89.1 | 86.8 | 84.4 |
| 37.2 | 62.0 | 56.4 | 59.5 | 61.9 | 58.5 |
Partly immunised | | | | | | |
| 16.9 | 2.9* | 1.6* | 4.0 | 6.9 | 5.7 |
| 16.4 | 29.8 | 7.3 | 30.7 | 15.9 | 20.2 |
| 15.5 | 30.0 | 13.7 | 10.1 | 20.4 | 17.0 |
| . . | . . | . . | . . | . . | . . |
| . . | . . | . . | . . | . . | . . |
| 23.0 | 36.1 | 42.2 | 39.6 | 37.5 | 37.5 |
Not immunised | | | | | | |
| 39.8 | 1.9* | 1.6* | 1.0* | 0.8 | 3.9 |
| 40.7 | 2.9* | 2.9 | 2.4 | 3.1 | 5.6 |
| 46.7 | 6.8 | 4.4 | 2.5 | 1.9 | 6.2 |
| . . | . . | 32.7 | 7.4 | 7.4 | 11.4* |
| . . | . . | 33.9 | 10.9 | 13.2 | 15.6 |
| 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 |
| 91.5 | 75.5 | 75.4 | 89.8 | 85.6 | 50.4 |
| 88.4 | 72.5 | 70.2 | 88.0 | 79.0 | 42.7 |
| 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
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).