论文标题：The introduction of ‘No jab, No school’ policy and the refinement of measles immunisation strategies in high-income countries

期刊：BMC Medicine

作者：Filippo Trentini, Piero Poletti, Alessia Melegaro and Stefano Merler

发表时间：2019/05/17

数字识别码：10.1186/s12916-019-1318-5

原文链接：http://t.cn/EKlGHEJ

微信链接：https://mp.weixin.qq.com/s/pDp7nmkQU8MtAitBcuplXg

最近发表在开放获取期刊BMC Medicine 上的一项研究显示，澳大利亚、爱尔兰、意大利、英国和美国现行的疫苗政策可能不足以实现和维持消除麻疹的目标，并且不足以预防未来麻疹的再度出现。

想要在这些国家实现并维持中长期的消除麻疹目标，可能还需要在现有政策的基础上按各国情况进一步加强免疫力度。麻疹消除的定义是在某一区域或其他特定地理范围内没有出现麻疹达12个月或以上。

意大利布鲁诺·科斯勒基金会和博科尼大学的一个研究团队利用计算机模型模拟了7个国家（澳大利亚、爱尔兰、意大利、新加坡、韩国、英国和美国）中麻疹免疫状况的演变。作者集中分析的国家都具有常规两剂麻疹接种项目，且小学接种率都较高，但各国在人口特征和疫苗接种史上有所不同。研究的目标是评估如果对现有防疫策略进行调整会产生什么效果，同时评估随时间推移高收入国家中易患麻疹的人口比例。

作者的预测最远至2050年，预测结果表明如果现行的疫苗政策不变，新加坡和韩国的麻疹易感人口比例将保持在7.5%以下，这两个国家过去的疫苗覆盖率都很高。此前的研究推测，无免疫力的人口比例（即最大易感率）需要低于7.5%，才能保证麻疹处于消除状态。

2018年，针对麻疹易感人口比例的研究显示，这一数字在英国为3.7%，在意大利为9.3%（意大利是几国中唯一一个高于7.5%的国家）。在澳大利亚、爱尔兰、英国和美国，常规接种项目的覆盖率需要持续达到95%以上，才能保证易感人口比例到2050年依然低于7.5%。

研究的第一作者Filippo Trentini博士说：“近年来，我们目睹麻疹在多个国家卷土重来，其中甚至包括世界卫生组织（WHO）已经认定的已达成麻疹消除目标的国家。这次麻疹再现主要是因为疫苗接种的覆盖率不理想。作为麻疹发病率最高的国家之一，意大利政府已经强制要求儿童在进入小学前接种麻疹疫苗。我们调查了这一政策及其他政策在7个高收入国家中加强疫苗接种率的潜力。”

研究的共同作者Stefano Merler博士补充道：“我们的结果表明，除了现行的疫苗接种计划，本研究中的大部分国家都能从入学强制接种政策中大大获益。我们发现这一政策对英国、爱尔兰和美国在未来几十年中保持稳定的免疫水平尤为重要，只有这样才能保证人群中具有免疫力的比例足够高，从而预防未来的疾病爆发。想要切实有效，入学强制接种需要覆盖至少40%的人群。”

在意大利，即便常规接种的覆盖率达到100%，2050年易感人群比例预计也将达到10%，因此想要消除麻疹需要额外的疫苗接种策略，这些策略既要覆盖入学儿童也要覆盖成年人。

摘要：

Background

In recent years, we witnessed a resurgence of measles even in countries where, according to WHO guidelines, elimination should have already been achieved. In high-income countries, the raise of anti-vaccination movements and parental vaccine hesitancy are posing major challenges for the achievement and maintenance of high coverage during routine programmes. Italy and France approved new regulations, respectively in 2017 and 2018, aimed at raising immunisation rates among children by introducing mandatory vaccination at school entry.

Methods

We simulated the evolution of measles immunity profiles in seven distinct countries for the period 2018–2050 and evaluated the effect of possible adjustments of immunisation strategies adopted in the past on the overall fraction and age distribution of susceptible individuals in different high-income demographic settings. The proposed model accounts for country-specific demographic components, current immunity gaps and immunisation activities in 2018. Vaccination strategies considered include the enhancement of coverage for routine programmes already in place and the introduction of a compulsory vaccination at primary school entry in countries where universal school enrolment is likely achieved.

Results

Our model shows that, under current vaccination policies, the susceptible fraction of the population would remain below measles elimination threshold only in Singapore and South Korea. In the UK, Ireland, the USA and Australia either the increase of coverage of routine programmes above 95% or the introduction of a compulsory vaccination at school entry with coverage above 40% are needed to maintain susceptible individuals below 7.5% up to 2050. Although the implementation of mandatory vaccination at school entry would be surely beneficial in Italy, strategies targeting adults would also be required to avoid future outbreaks in this country.

Conclusions

Current vaccination policies are not sufficient to achieve and maintain measles elimination in most countries. Strategies targeting unvaccinated children before they enter primary school can remarkably enhance the fulfilment of WHO targets.

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期刊介绍:

BMC Medicine (https://bmcmedicine.biomedcentral.com/, 9.088 - 2-year Impact Factor,9.41 - 5-year Impact Factor) is the flagship medical journal of the BMC series. An open access, open peer-reviewed general medical journal, BMC Medicine publishes outstanding and influential research in all areas of clinical practice, translational medicine, medical and health advances, public health, global health, policy, and general topics of interest to the biomedical and sociomedical professional communities. We also publish stimulating debates and reviews as well as unique forum articles and concise tutorials.

（来源：科学网）