Department of Social and Preventive Medicine, Laval University.
Institut National de Santé Publique du Québec.
Clin Infect Dis. 2017 Oct 1;65(7):1094-1102. doi: 10.1093/cid/cix510.
The effect of age at first dose on the immunogenicity of a 2-dose pediatric schedule of measles-mumps-rubella (MMR) or measles-mumps-rubella-varicella (MMRV) vaccine was assessed in children born to mostly vaccinated mothers.
Immunogenicity data among children given their first measles vaccine dose between 11 and 22 months of age were pooled from 5 randomized controlled trials conducted in Europe and the United States between 2004 and 2010. Measles antibody titers were measured by enzyme-linked immunosorbent assay before and after each dose; geometric mean concentrations (GMCs) and the proportion seronegative (GMC <150 mIU/mL) were derived by age at first dose.
Among 5542 children given a first measles vaccine dose at 11, 12, 13-14, and 15-22 months of age, the proportion seronegative decreased from 8.5% to 3.2%, 2.4%, and 1.5%, respectively (P < .001), whereas GMCs increased with older age measles vaccine initiation (P < .001). MMRV induced higher GMCs than MMR (P < .001). First and second dose GMCs were highly correlated (Spearman coefficient = 0.8).
As previously noted among infants born to mothers with history of wild-type measles, antibody responses among children born to vaccinated mothers were reduced based on earlier administration of their first measles vaccine dose at ≤12 vs ≥15 months of age. Negative effects of earlier age at first measles vaccine dose persisted after the second dose. The measles elimination goal may require a careful balance between earlier infant protection and the risk of reduced antibody responses and secondary vaccine failure among successive birth cohorts systematically initiated to measles vaccination <15 months of age.
在主要接种过疫苗的母亲所生的儿童中，评估了第 1 剂年龄对两剂儿童麻疹-腮腺炎-风疹（MMR）或麻疹-腮腺炎-风疹-水痘（MMRV）疫苗免疫原性的影响。
从 2004 年至 2010 年在欧洲和美国进行的 5 项随机对照试验中，汇总了在 11 至 22 个月龄之间接受第 1 剂麻疹疫苗的儿童的免疫原性数据。在每次接种前和接种后通过酶联免疫吸附试验测量麻疹抗体滴度；按第 1 剂年龄得出几何平均浓度（GMC）和血清阴性率（GMC<150 mIU/mL）。
在 5542 名 11、12、13-14 和 15-22 月龄接受第 1 剂麻疹疫苗的儿童中，血清阴性率分别从 8.5%降至 3.2%、2.4%和 1.5%（P<0.001），而 GMC 随着麻疹疫苗起始年龄的增加而增加（P<0.001）。MMRV 诱导的 GMC 高于 MMR（P<0.001）。第 1 剂和第 2 剂 GMC 高度相关（Spearman 系数=0.8）。
正如既往在母亲有野病毒感染史的婴儿中所观察到的那样，与 15 个月龄以上相比，≤12 个月龄时首次接种麻疹疫苗的儿童，其抗体反应降低。在接种第 2 剂后，第 1 剂麻疹疫苗接种年龄更早的负面效应仍持续存在。麻疹消除目标可能需要在婴儿早期保护与在按序接种麻疹疫苗<15 个月龄的连续出生队列中降低抗体反应和继发疫苗失败的风险之间，进行仔细平衡。
