The level of whooping cough (pertussis) immunisation has declined significantly, according to figures seen by The Irish Times. National vaccination levels have fallen by 10 per cent in a year.
Only 66 per cent of children aged 12 months completed the three-part vaccination programme for this potentially dangerous illness by the end of the third quarter of 2001. This compares with a national uptake of 76 per cent at the same time in 2000.
The worst uptake was in the Eastern Regional Health Authority, where pertussis vaccination at 12 months has dropped from 73 per cent to 60 per cent. In the latest figures, the South Eastern Health Board had the highest level of whooping cough immunisation at 81 per cent. The year-on-year drop of 6 per cent within this region was also the lowest for all health board areas for which figures are available.
The latest statistics are part of a worrying trend of decreasing vaccination for a range of infectious diseases. Immunisation rates against measles, mumps and rubella (MMR) have dropped below 60 per cent in parts of Dublin. Whooping cough is particularly dangerous under the age of one with a high incidence of severe pneumonia. "In order to best protect infants, they should receive their immunisation at the time they are due, that is at two, four and six months," said Dr Darina O'Flanagan. director of the National Disease Surveillance Centre. Her comments reflect anxiety at the centre that children are being vaccinated later than recommended. The uptake of pertussis vaccination at 24 months of age has remained stable at 81 to 83 per cent of the target population.
However, it is also possible that the uptake figures for infants aged 12 months at the end of 2001 will not improve at 24 months, indicating that parents' concern about MMR vaccine has spread to the primary immunisation of infants against whooping cough, diphtheria, polio and tetanus.
Public fears of a connection between the MMR vaccine, which is given at 12 to 15 months, and autism are thought to be responsible for the sharp drop in uptake. Extensive international research has failed to confirm any link.
Vaccination levels for any infectious disease need to be at 95 per cent for a programme to be effective.