Zanetta Dirce M T, Cabrera Eliana M S, Azevedo Raymundo S, Burattini Marcelo N, Massad Eduardo
Department of Epidemiology and Public Health, School of Medicine of São José do Rio Preto (FAMERP), São José do Rio Preto, SP, Brazil.
Vaccine. 2003 Sep 8;21(25-26):3795-800. doi: 10.1016/s0264-410x(03)00315-3.
Rubella vaccine was introduced in the official immunization calendar of the State of São Paulo, in 1992, at 15 months of age, following a mass vaccination targeting all children between 1 and 10 years of age. This mixed strategy was designed taking into account serological data and mathematical models to estimate the optimal ages for vaccination. To evaluate the efficacy of routine vaccination on rubella infection in São José do Rio Preto, State of São Paulo, 8 years after the introduction of vaccine, a seroprevalence survey was carried out in December 2000, comprising 1,536 subjects aging from 6 months to 25 years. Rubella specific IgG was detected in blood samples by enzyme-linked immunosorbent assay (ELISA). From 18 months to 5 years of age (covered by a mass vaccination campaign 6 months before the study) the seroprevalence was above 90%. From 6 to 8 years of age (vaccinated by routine schedule at 15 months), the seroprevalence was 76%. From 9 to 18 years of age (vaccinated at the mass campaign that introduced the vaccine 8 years before) the seroprevalence was about 85%. After 20 years of age, protection was acquired by previous infection, as they were not covered by any vaccine program. From 20 to 25 years of age, the seroprevalence was 70%. As the seroprevalence remains low at ages not vaccinated, it should be expected low infection rates at this age window. Despite this, the present situation deserves care, as routine vaccination is given a protection below the minimum level necessary (80%). The efficacy of the proposed strategy depends on better routine vaccination coverage. A second dose of vaccine should also be considered.
风疹疫苗于1992年被纳入圣保罗州的官方免疫规划，接种年龄为15个月，此前针对所有1至10岁儿童开展了大规模疫苗接种。制定这一混合策略时考虑了血清学数据和数学模型，以估算最佳接种年龄。为评估疫苗引入8年后圣保罗州里奥普雷图河畔圣若泽市风疹感染常规疫苗接种的效果，2000年12月开展了一项血清流行率调查，涵盖1536名年龄在6个月至25岁之间的受试者。通过酶联免疫吸附测定（ELISA）检测血样中的风疹特异性IgG。18个月至5岁年龄段（在研究前6个月开展了大规模疫苗接种活动）的血清流行率高于90%。6至8岁年龄段（按常规程序在15个月时接种疫苗）的血清流行率为76%。9至18岁年龄段（在8年前引入疫苗的大规模活动中接种疫苗）的血清流行率约为85%。20岁之后，因既往感染获得了保护，因为他们未被任何疫苗接种计划覆盖。20至25岁年龄段的血清流行率为70%。由于未接种疫苗年龄段的血清流行率仍然较低，预计该年龄区间的感染率也较低。尽管如此，目前的情况仍需关注，因为常规疫苗接种提供的保护低于必要的最低水平（80%）。所提议策略的效果取决于更好的常规疫苗接种覆盖率。还应考虑接种第二剂疫苗。
