Impact of adverse publicity on MMR vaccine uptake: a population based analysis of vaccine uptake records for one million children, born 1987-2004.

AIMS

To determine the impact of adverse publicity on MMR uptake and measles susceptibility, including whether vaccination is delayed and the role of deprivation.

METHODS

A population database for all Scotland containing immunisation records for over one million children (n = 1,079,327) born 1987-2004 was analysed. MMR uptake was determined by birth cohort and deprivation category. "Final" uptake (at approx age 6 years) was predicted by linear regression by birth cohort. Measles susceptibility in 1998 and 2003 was determined by postcode sector and district for cohorts combined to construct nursery and primary school age groups.

RESULTS

There is evidence of a slight rise in late uptake, but insufficient to compensate for underlying declines. Late vaccination continues to be associated with deprivation, while the most affluent tend to be vaccinated promptly, or not at all. Predicted figures for "final" MMR1 uptake are over 90%, but under 95%. Measles susceptibility has increased significantly in nursery children, with an eightfold rise in the number of districts with greater than 20% susceptibility in this group (from 3 to 25).

CONCLUSIONS

Increased measles susceptibility in nursery children is concerning, particularly in the most vulnerable areas. These figures are likely to increase in the future, as MMR uptake has not yet returned to the previous higher level. Increased susceptibility levels can also be expected in primary schools in the future, as levels of late uptake are insufficient to compensate. Predicted figures for "final" MMR1 uptake are under the herd immunity threshold and campaigns may be required to increase uptake among future primary school children.