麻疹是儿童死亡的重要原因,尽管有安全且节省成本的含麻疹疫苗(MCV)。在麻疹持续传播的国家,建议在9月龄时使用首次MCV剂量(MCV1)。在麻疹风险较低的国家12个月。为了评估提高MCV1的年龄是否有益,我们对MCV1在9个月以下婴儿中的获益和风险进行了系统评价和荟萃分析.
对于本系统综述和荟萃分析,我们搜索了MEDLINE,EMBASE,Scopus,Proquest,全球卫生,世卫组织图书馆数据库,和世卫组织信息共享机构数据库,并咨询了专家。我们纳入了随机和准随机对照试验,疫情调查,以及不限制发表日期的队列和病例对照研究,其中MCV1应用于9个月以下的婴儿.我们于2015年6月2日进行了文献检索,并于2019年1月14日进行了更新。我们评估了:血清转化的婴儿比例,几何平均抗体滴度,贪婪,细胞免疫,免疫期限,疫苗功效,疫苗有效性,和安全。我们使用随机效应模型来得出终点的汇总估计,在适当的地方。我们使用建议分级来评估方法学质量,评估,发展,和评价准则。
我们的搜索确定了1156项研究,其中1071人接受了资格筛选。351个有资格进行全文筛选,符合所有纳入标准的56项研究的数据被用于分析.血清转化的婴儿比例从4月龄接种MCV1的婴儿的50%(95%CI29-71)增加到8月龄接种疫苗的85%(69-97)。4-8个月接种MCV1的婴儿与9个月或以上接种MCV1的婴儿的合并几何平均滴度比为0·46(95%CI0·33-0·66;I2=99·9%,p<0·0001)。只有一项研究报道了亲合力,并表明在6个月大的MCV1给药后,亲合力较低,免疫持续时间较短,而在9个月大(p=0·0016)或12个月大(p<0·001)。在施用MCV1时没有发现年龄对细胞免疫的影响。一项研究报告说,在4·5月龄接种MCV1的婴儿中,针对实验室确认的麻疹病毒感染的疫苗效力为94%(95%CI74-98)。MCV1在9个月以下婴儿中对麻疹的综合疫苗有效性为58%(95%CI9-80;I2=84·9%,p<0·0001)。从接种MCV1的9个月以下婴儿的研究内比较得出的综合疫苗有效性估计为51%(95%CI-44至83;I2=92·3%,p<0·0001),对于接种疫苗的9个月及以上的人,这一比例为83%(76-88;I2=93·8%,p<0·0001)。在9个月以下的婴儿和9个月以上的婴儿之间,MCV1给药后不良事件的风险没有差异。总的来说,证据质量从中等到极低不等.
对小于9个月的婴儿给予MCV1诱导良好的免疫反应,其中血清转化的婴儿比例随着疫苗接种年龄的增加而增加。在9个月之前接受MCV1的婴儿中有很大一部分受到保护,疫苗是安全的,尽管当MCV1在年龄较大时,发现抗体滴度和疫苗有效性较高。对于麻疹高危人群,建议对9个月以下的婴儿给予MCV1是降低麻疹相关死亡率和发病率的重要一步。
谁。
Measles is an important cause of death in children, despite the availability of safe and cost-saving measles-containing vaccines (MCVs). The first MCV dose (MCV1) is recommended at 9 months of age in countries with ongoing measles transmission, and at 12 months in countries with low risk of measles. To assess whether bringing forward the age of MCV1 is beneficial, we did a systematic
review and meta-analysis of the benefits and risks of MCV1 in infants younger than 9 months.
For this systematic
review and meta-analysis, we searched MEDLINE, EMBASE, Scopus, Proquest, Global Health, the WHO library database, and the WHO Institutional Repository for Information Sharing database, and consulted experts. We included randomised and quasi-randomised controlled trials, outbreak investigations, and cohort and case-control studies without restriction on publication dates, in which MCV1 was administered to infants younger than 9 months. We did the literature search on June 2, 2015, and updated it on Jan 14, 2019. We assessed: proportion of infants seroconverted, geometric mean antibody titre, avidity, cellular immunity, duration of immunity, vaccine efficacy, vaccine effectiveness, and safety. We used random-effects models to derive pooled estimates of the endpoints, where appropriate. We assessed methodological quality using the Grading of Recommendations, Assessment, Development, and Evaluation guidelines.
Our search identified 1156 studies, of which 1071 were screened for eligibility. 351 were eligible for full-text screening, and data from 56 studies that met all inclusion criteria were used for analysis. The proportion of infants who seroconverted increased from 50% (95% CI 29-71) for those vaccinated with MCV1 at 4 months of age to 85% (69-97) for those were vaccinated at 8 months. The pooled geometric mean titre ratio for infants aged 4-8 months vaccinated with MCV1 compared with infants vaccinated with MCV1 at age 9 months or older was 0·46 (95% CI 0·33-0·66; I2=99·9%, p<0·0001). Only one study reported on avidity and suggested that there was lower avidity and a shorter duration of immunity following MCV1 administration at 6 months of age than at 9 months of age (p=0·0016) or 12 months of age (p<0·001). No effect of age at MCV1 administration on cellular immunity was found. One study reported that vaccine efficacy against laboratory-confirmed measles virus infection was 94% (95% CI 74-98) in infants vaccinated with MCV1 at 4·5 months of age. The pooled vaccine effectiveness of MCV1 in infants younger than 9 months against measles was 58% (95% CI 9-80; I2=84·9%, p<0·0001). The pooled vaccine effectiveness estimate from within-study comparisons of infants younger than 9 months vaccinated with MCV1 were 51% (95% CI -44 to 83; I2=92·3%, p<0·0001), and for those aged 9 months and older at vaccination it was 83% (76-88; I2=93·8%, p<0·0001). No differences in the risk of adverse events after MCV1 administration were found between infants younger than 9 months and those aged 9 months of older. Overall, the quality of evidence ranged from moderate to very low.
MCV1 administered to infants younger than 9 months induces a good immune response, whereby the proportion of infants seroconverted increases with increased age at vaccination. A large proportion of infants receiving MCV1 before 9 months of age are protected and the vaccine is safe, although higher antibody titres and vaccine effectiveness are found when MCV1 is administered at older ages. Recommending MCV1 administration to infants younger than 9 months for those at high risk of measles is an important step towards reducing measles-related mortality and morbidity.
WHO.