There are now 25 postcode districts. where more than one in five nursery school children is potentially at risk of catching measles, compared with just three in 1998, when unfounded claims that the vaccine might be linked to autism provoked widespread alarm.
MMR was introduced across the UK in 1988. The recommended schedule is for the first dose to be given at the age of 13 months, with the second dose at between 3 years and 5 years of age.
The researchers looked at the vaccination records for Scotland for all children born between 1987 and 2004, accounting for over one million children.
The records show that the sharpest decline began for children born from 1999 onwards, rather than for those born in 1997 as might be expected. This suggests that the negative publicity had a gradual but cumulative effect, say the authors.
The most affluent sectors of the population tended to either have their children vaccinated early or not at all, the figures show. But parents in the most deprived areas of Scotland tended to delay vaccinating their children.
The increased risks of measles to nursery school children are concerning, particularly in the areas of greatest deprivation, where the risk of measles outbreaks would add to existing health inequalities, say the authors.
Although rates of MMR vaccine uptake have increased across Scotland, these have not yet reached the levels before 1998, and are not expected to reach the levels required for population protection among young schoolchildren, say the authors.