The impact of varicella vaccination on varicella-related hospitalization rates: global data review

Abstract Objective: To describe the impact of varicella vaccination on varicella-related hospitalization rates in countries that implemented universal vaccination against the disease. Data source: We identified countries that implemented universal vaccination against varicella at the http://apps.who.int/immunization_monitoring/globalsummary/schedules site of the World Health Organization and selected articles in Pubmed describing the changes (pre/post-vaccination) in the varicella-related hospitalization rates in these countries, using the Keywords "varicella", "vaccination/vaccine" and "children" (or) "hospitalization". Publications in English published between January 1995 and May 2015 were included. Data synthesis: 24 countries with universal vaccination against varicella and 28 articles describing the impact of the vaccine on varicella-associated hospitalizations rates in seven countries were identified. The US had 81.4%–99.2% reduction in hospitalization rates in children younger than four years, 6–14 years after the onset of universal vaccination (1995), with vaccination coverage of 90%; Uruguay: 94% decrease (children aged 1–4 years) in six years, vaccination coverage of 90%; Canada: 93% decrease (age 1–4 years) in 10 years, coverage of 93%; Germany: 62.4% decrease (age 1–4 years) in 8 years, coverage of 78.2%; Australia: 76.8% decrease (age 1–4 years) in 5 years, coverage of 90%; Spain: 83.5% decrease (age <5 years) in four years, coverage of 77.2% and Italy 69.7%–73.8% decrease (general population), coverage of 60%–95%. Conclusions: The publications showed variations in the percentage of decrease in varicella-related hospitalization rates after universal vaccination in the assessed countries; the results probably depend on the time since the implementation of universal vaccination, differences in the studied age group, hospital admission criteria, vaccination coverage and strategy, which does not allow direct comparison between data.

摘要 研究目的：阐述实施水痘（varicella）全民免疫接种的国家中，水痘疫苗接种对水痘相关住院率的影响。
数据来源：通过世界卫生组织（World Health Organization, WHO）的http://apps.who.int/immunization_monitoring/globalsummary/schedules 网站，筛选实施水痘全民免疫接种的国家；并在PubMed数据库中，以“varicella”“vaccination/vaccine”及“children”或“hospitalization”为关键词，检索描述上述国家接种前后水痘相关住院率变化的文献。纳入1995年1月至2015年5月期间发表的英文文献。
数据综合：共纳入24个实施水痘全民免疫接种的国家，以及覆盖7个国家的28篇阐述疫苗对水痘相关住院率影响的文献。1995年美国启动全民水痘接种后，疫苗接种覆盖率达90%，4岁以下儿童及6~14岁儿童的住院率降幅达81.4%~99.2%；乌拉圭在接种6年后，1~4岁儿童住院率下降94%，接种覆盖率为90%；加拿大接种10年后，1~4岁儿童住院率下降93%，覆盖率达93%；德国接种8年后，1~4岁儿童住院率下降62.4%，覆盖率为78.2%；澳大利亚接种5年后，1~4岁儿童住院率下降76.8%，覆盖率90%；西班牙接种4年后，5岁以下儿童住院率下降83.5%，覆盖率77.2%；意大利全人群住院率下降69.7%~73.8%，接种覆盖率为60%~95%。
研究结论：纳入的文献显示，各评估国家实施全民水痘接种后，水痘相关住院率的降幅存在差异；该结果可能受全民接种实施时长、研究年龄组差异、住院收治标准、疫苗接种覆盖率及接种策略等因素影响，因此不同国家的数据无法直接进行比较。