Aim: Vaccine studies that evaluate the persistence of protection following immunisation require subjects to continue participation in a research protocol over many years. As parents’ attitudes and opinions may change over time, and with experience of research, it is important to consider the factors influencing parents’ decision-making about their child’s continued participation in such prolonged vaccine studies.

Method: Parental views about participation of their child in a one-year follow-up vaccine study were explored by means of a self-administered questionnaire. Of the 254 eligible parents, 187 took part (74 per cent).

Results: Parents who provided consent were more likely to agree that having a home visit to take blood was very helpful (p=0.005) and that information obtained during the earlier part of the study influenced their decision to take part in a follow-up study (p<o.ooo1). Parents who did not consent to their child’s participation were more likely to report the presence of personal reasons as a variable influencing their decision (p<0.0001).

Conclusions: The relationship between study staff and parents is the cornerstone for success in performing studies involving vaccines and children. Provision of clear study information (oral and written) and offering the convenience of home visits are important in retaining participants in paediatric vaccine trials.