[Impact of active research for vaccination information in children with incomplete or lost vaccination records]

We estimated the accuracy of the information in the vaccination booklet of 8,457 children. The booklets were classified as complete (CC), incomplete (CI) or lost (CP). For children in the CI or CP categories, an active search was done in their providers' records and we assessed their vaccine coverage. Overall, the booklet provided accurate information for 88.6% of the 7,646 children who were vaccinated at least once. Among the 711 children in the CI category, the active search showed that 79% had received all their vaccines at age two years whereas this proportion was 59% among the 280 children in the CP category. The active search increased the vaccine coverage in the population by 4%.

The majority of children in the CI or CP categories whose parents report that they received all their vaccines are in fact adequately vaccinated.