Sage Analytica, Portland, ME, USA.
Department of Genetics and Evolutionary Biology, University of São Paulo, São Paulo, Brazil.
Lancet Glob Health. 2019 Feb;7(2):e249-e256. doi: 10.1016/S2214-109X(18)30455-8.
Understanding the real-world effect of pneumococcal conjugate vaccines (PCVs) on pneumonia mortality is crucial because of the expectation that increased PCV use will substantially reduce the burden of pneumonia deaths in children younger than 5 years. However, few post-vaccine introduction studies have estimated the benefits of PCV use on childhood mortality and results have been inconsistent. Therefore, we set out to assess the effect of introduction of ten-valent pneumococcal conjugate vaccine (PCV10) on pneumonia mortality in children in Brazil.
In this retrospective observational study, we used publicly available mortality data of children aged 3-59 months in Brazil. We separated data by age group (3-11 months, 3-23 months, and 3-59 months) and stratified data by three different socioeconomic factors of Brazilian municipalities (in 2010): Human Development Index, proportion of children living in extreme poverty, and proportion of mothers with no primary education. We first examined long-term trends in childhood pneumonia mortality in Brazil (from 1980 to 2014). We then assessed the effect of PCV10-introduced in Brazil in 2010-both nationally and in municipalities stratified by socioeconomic status, with a synthetic control approach as our primary analytical method.
Between 1980 and 2010, a period during which Brazil's Human Development Index rose substantially, national pneumonia mortality in children younger than 5 years decreased from about 150 to 15 deaths per 100 000 children younger than 5 years. Despite rapid uptake of PCV10 after its introduction in 2010, we observed a further vaccine-associated decline of about 10% in national childhood pneumonia mortality with our primary analytical method, with a high degree of uncertainty in the estimates. We observed larger reductions in municipal childhood pneumonia mortality in all three age groups (3-11 months, 3-23 months, and 3-59 months) in municipalities with a high percentage of extreme childhood poverty and mothers with no primary education, with the largest decrease observed in children aged 3-23 months in municipalities with low maternal education (24%, 95% credible interval 7-35).
The large reduction observed from 1980 to 2010 in national pneumonia mortality in children younger than 5 years underscores that improvements in nutrition, hygiene, education, and health care have an important role in reducing pneumonia mortality. Although the PCV-associated reduction in childhood pneumonia mortality at the national level was modest, we found that PCV led to larger reductions in low-income municipalities. Similarly, large benefits might occur when PCVs are introduced in other low-income settings.
Bill & Melinda Gates Foundation and National Institute of Allergy and Infectious Diseases.
了解肺炎球菌结合疫苗(PCV)在现实世界中对肺炎死亡率的影响至关重要,因为人们预计,增加 PCV 的使用将大大降低 5 岁以下儿童肺炎死亡人数。然而,很少有疫苗接种后引入的研究估计了 PCV 使用对儿童死亡率的益处,而且结果不一致。因此,我们着手评估 10 价肺炎球菌结合疫苗(PCV10)在巴西儿童中的引入对肺炎死亡率的影响。
在这项回顾性观察性研究中,我们使用了巴西 3-59 个月儿童的公开死亡率数据。我们按年龄组(3-11 个月、3-23 个月和 3-59 个月)对数据进行了划分,并按巴西市政当局的三个不同社会经济因素(2010 年)对数据进行了分层:人类发展指数、生活在赤贫中的儿童比例和没有小学教育的母亲比例。我们首先研究了巴西儿童肺炎死亡率的长期趋势(1980 年至 2014 年)。然后,我们评估了 2010 年在巴西引入的 PCV10 的效果,无论是在全国范围内,还是在按社会经济地位分层的市政当局中,都采用合成对照方法作为我们的主要分析方法。
在巴西人类发展指数大幅上升的 1980 年至 2010 年期间,5 岁以下儿童全国肺炎死亡率从每 10 万 5 岁以下儿童约 150 人下降到 15 人。尽管 2010 年 PCV10 引入后迅速普及,但我们使用主要分析方法观察到全国儿童肺炎死亡率进一步下降了约 10%,但估计存在高度不确定性。我们在所有三个年龄组(3-11 个月、3-23 个月和 3-59 个月)中观察到,在赤贫儿童比例较高和没有小学教育的母亲比例较高的市政当局中,儿童肺炎死亡率下降幅度更大,在母亲教育程度较低的市政当局中,3-23 个月儿童的降幅最大(24%,95%置信区间为 7-35)。
1980 年至 2010 年 5 岁以下儿童全国肺炎死亡率的大幅下降表明,营养、卫生、教育和医疗保健的改善在降低肺炎死亡率方面发挥了重要作用。尽管 PCV 相关的儿童肺炎死亡率在全国范围内的下降幅度较小,但我们发现,PCV 导致贫困程度较高的低收入市政当局的死亡率下降幅度更大。同样,在其他低收入环境中引入 PCV 可能会产生较大的益处。
比尔及梅琳达·盖茨基金会和美国国立过敏和传染病研究所。