Changes in the prevalence of the measles, rubella, varicella-zoster, and mumps virus antibody titers in Japanese pregnant women

• Immunity against infectious diseases influences both the mother and fetus.
• Antibody titers are low during childbearing age.
• Acquired immunity is dependent on vaccinations and natural infections.
• Vaccination is necessary at a young age.
• The timing of vaccination is important.

In the present study, immunity against infectious diseases, which are capable of influencing both the mother and fetus during pregnancy and the infant in the postnatal period, were assessed in pregnant women to elucidate the necessity of vaccination during the childbearing age. It was determined that there was a trend of increases in the proportion of patients that had low antibody titers observed at a young age. Overall, after adjusting for age, low antibody titers of measles (≤4 via the neutralization test [NT]), rubella (≤16 via the hemagglutination inhibition [HI]), and varicella and mumps (plus minus or negative on the enzyme-linked immunosorbent assay [EIA]) indicated that the rates of necessity for vaccination against measles, rubella, varicella, and mumps were 27.6%, 16.1%, 3.9%, and 23.8%, respectively. In Japan, acquired immunity for measles, rubella, and mumps was dependent on vaccination, whereas acquired immunity for varicella was dependent on natural infection. We recommend that women be vaccinated after delivery, as these vaccines are live, and thereby, are contraindicated during pregnancy.