Abstract

Objective: To establish the most appropriate age ranges for the use of human normal immunoglobulin and MMR vaccine as postexposure prophylaxis.

Design: Review of literature and of laboratory confirmed measles cases.

Setting: England and Wales and countries with a similar measles epidemiological profile.

Patients: Women of childbearing age and infants.

Main outcome measures: The risk of measles, maternally derived measles antibody levels and the response to measles containing vaccines in infants.

Results: By 4 to 5 months of age, only 28–45% of infants born to women from highly vaccinated populations have protective levels of measles antibody. In the postvaccine era, between 74% and 80% of infants vaccinated between 6 and 9 months respond to vaccine, and around 67% have clinical protection from measles vaccination.

Conclusion: This study suggests that many infants being born in the UK will become susceptible to measles before 6 months and will be able to respond to vaccine between 6 and 9 months of age. It is proposed that current guidance is changed to recommend passive immunisation with human normal immunoglobulin for most infants exposed to measles below 6 months of age. For infants aged 6 months or over exposed to measles, vaccination with MMR may be given.