We conducted a prospective birth cohort study in rural Sudan to assess measles virus (MV)-specific antibody levels at different time points in infancy. Dried blood spots were collected on filter paper at birth (cord blood) and at ages 6, 12 and 24 months (heel-prick). Maternally derived MV-specific antibody levels were high in cord blood samples, but at the age of 6 months had dropped below cut-off values in half of the infants. By extrapolation it was concluded that the current Expanded Programme of Immunization (EPI) target age for measles vaccination of 9 months was an appropriate choice for this area. At the age of 24 months acquired MV-specific antibodies were detected in 65-85% of the cohort, which corresponded well with the 79% of infants reported to be vaccinated by this age. This study demonstrates the usefulness of filter paper blood samples for seroepidemiological studies in developing countries.

doi.org/10.1017/S0950268805004620, hdl.handle.net/1765/39680
Epidemiology and Infection
Department of Virology

Ibrahim, S. A., Abdallah, A., Saleh, E. A., Osterhaus, A., & de Swart, R. (2006). Measles virus-specific antibody levels in Sudanese infants: A prospective study using filter-paper blood samples. Epidemiology and Infection, 134(1), 79–85. doi:10.1017/S0950268805004620