Background: In order to control the spread of rubella and reduce the risk for congenital rubella syndrome, an additional rubella vaccination program was set up for all secondary school students since 2008 in Zhejiang, China.
Methods: We conducted a descriptive analysis of rubella incidence among different age groups from 2005 to 2015 and a serosurvey of female subjects aged 15-39 years to understand the possible effects of this immunization program.
Results: The average annual rubella incidence rate had decreased from 15.86 per 100,000 population (2005-2007) to 0.75 per 100,000 population (2013-2015) in Zhejiang. The decrease in the rate of rubella incidence in girls aged 15-19 years was more accelerated (from 138.30 to 0.34 per 100,000) than in the total population during 2008-2015 (from 32.20 to 0.46 per 100,000). Of 1225 female subjects in the serosurvey, 256 (20.9%) were not immune to rubella. The proportion of subjects immune to rubella was significantly different among different age groups (Wald χ2 = 22.19, p = 0.000), and subjects aged 15-19 years old had the highest immunity (88.0%). Rubella antibody levels were significantly lower in women aged 25-30 years with 26.7% of them not immune, followed by the group aged 20-24 years (25.0%) and 30-35 years (24.5%).
Conclusions: Rubella vaccine included in the Expanded Program on Immunization together with vaccination activities for secondary school students can help in rubella control, particularly in targeted age groups in the program. Seroprevalence of antibodies to the rubella virus amongst the female population within childbearing age in Zhejiang, China, is still too low to provide immunity. In addition to vaccination programs in the secondary schools, rubella vaccination should also be encouraged in women of childbearing age, which can be done effectively combined with pre-marital examination in China.
Keywords: Female; Immunity; Rubella; Rubella containing vaccine (RCV).