Objectives : To investigate the prevalence of rubella HI antibody among pregnant women in relation to changes in the recommended age for rubella-containing vaccination.
Methods : A total of 659 primiparous women were included in this study. All subjects were ≥20 years old at the time of delivery in our hospital during the 5-year period from January 2008 to December 2012. Rubella HI antibody titers were measured. Subjects were divided into four groups according to their date of birth and retrospectively analyzed : i) single-dose mass vaccination in junior high school generation ; ii) “interim measures generation” ; iii) single-dose vaccination in infancy generation ; and iv) infancy plus catch-up MR two-dose vaccination generation. HI antibody titers ≤1 : 16 was defined as a low antibody titer.
Results : The percentage of cases with low antibody titers in the total study population was 20.2%. The percentages of cases with low antibody titers in each group were : i) 20.4%, ii) 18.2%, iii) 30.6%, and iv) 31.6%.
Conclusion : The percentage of low antibody titers among all cases was comparable to other reports. The results suggested that rubella seroprevalence was low among those in the generation including and subsequent to the single-dose vaccination in infancy generation.