MMR vaccination, measles epidemiology and sero-surveillance in the Republic of Ireland.

Objective: Following the introduction of a national measles and subsequent MMR vaccination programme, to determine the susceptibility of 3-14-year-old children to measles, mumps and rubella and to relate the results to the epidemiology of measles and the need for vaccination policy changes.
Design: Cross-sectional sero-survey and trends in measles notifications and mortality.
Setting: Paediatric hospital outpatient departments in Dublin.
Subjects: Sera were collected from 837 children attending the clinics in 1991 and 1992.
Results: The prevalence of antibodies in children aged 3-6, 7-10 and 11-14 years was 84, 83 and 95% for measles; 48, 60 and 65% for mumps; and 78, 63 and 74% for rubella, respectively. The prevalence of mumps antibodies may be underestimated. Ninety-six per cent of girls aged 13-14 years had rubella antibodies. A widespread outbreak of measles occurred in 1993. Over recent years, an increasing proportion of measles notifications were in older children.
Conclusion: Given sub-optimal uptake of MMR vaccine, outbreaks of infection in pre- and primary school children are inevitable. In such circumstances, a 2-shot MMR vaccine programme with high uptake is essential to prevent a shift of disease into older age groups.