BACKGROUND After pneumococcal disease and colonization have been controlled through vaccination campaigns, a reduced pneumococcal conjugate vaccine (PCV) schedule may be sufficient to sustain that control at reduced costs. METHODS We investigated whether a single primary dose and booster dose (1p+1) of the 10-valent PCV (PCV10) would be noninferior to alternative dose schedules in sustaining control of carriage of pneumococcal serotypes included in the vaccine. In Nha Trang, Vietnam, an area in which PCV had not been used previously, a PCV10 catch-up campaign was conducted in which the vaccine was offered to children younger than 3 years of age, after which a cluster-randomized trial was conducted in which children received PCV10 at 2, 3, and 4 months of age (3p+0 group); at 2, 4, and 12 months of age (2p+1 group); at 2 and 12 months of age (1p+1 group); or at 12 months of age (0p+1 group). Annual carriage surveys in infants (4 to 11 months of age) and toddlers (14 to 24 months of age) were conducted from 2016 through 2020. The primary end point was protection against carriage of vaccine serotypes, evaluated in a noninferiority analysis in the 1p+1 group as compared with the 2p+1 and 3p+0 groups, 3.5 years after vaccine introduction (noninferiority margin, 5 percentage points). Noninferiority of the 0p+1 schedule was also evaluated. RESULTS In 2016, before the introduction of PCV10, vaccine-serotype carriage was found in 160 of 1363 infants (11.7%); in 2020, vaccine-serotype carriage was found in 6 of 333 (1.8%), 5 of 340 (1.5%), and 4 of 313 (1.3%) infants in the 1p+1, 2p+1, and 3p+0 groups, respectively, indicating noninferiority of 1p+1 to 2p+1 (difference, 0.3 percentage points; 95% confidence interval [CI], -1.6 to 2.2) and to 3p+0 (difference, 0.5 percentage points; 95% CI, -1.4 to 2.4). Similarly, 1p+1 was noninferior to 2p+1 and 3p+0 for protection against vaccine-serotype carriage among toddlers. In 2016, carriage of serotype 6A was found in 99 of 1363 infants (7.3%); in 2020, it was found in 12 of 333 (3.6%), 10 of 340 (2.9%), and 3 of 313 (1.0%) infants in the 1p+1, 2p+1, and 3p+0 groups, respectively. The 0p+1 schedule was also noninferior to the other three dose schedules among infants and toddlers, although cross-protection against serotype 6A was less common than with the other vaccination schedules. No PCV10-associated severe adverse effects were observed. CONCLUSIONS A reduced vaccination schedule involving a single primary dose and booster dose of PCV10 was noninferior to alternative schedules in protecting against vaccine-serotype carriage in infants and toddlers. (Funded by the Bill and Melinda Gates Foundation and others; ClinicalTrials.gov number, NCT02961231.).

中文翻译：

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减少 PCV10 剂量方案对越南肺炎球菌携带的影响。


背景 在通过疫苗接种运动控制肺炎球菌疾病和定植后，减少肺炎球菌结合疫苗 （PCV） 计划可能足以以较低的成本维持这种控制。方法 我们调查了 10 价 PCV （PCV10） 的单一主要剂量和加强剂量 （1p+1） 在维持对疫苗中包含的肺炎球菌血清型携带的控制方面是否不劣于替代剂量方案。在越南芽庄，一个以前没有使用 PCV 的地区，开展了 PCV10 补种运动，向 3 岁以下的儿童提供疫苗，之后进行了一项整群随机试验，儿童在 2、3 和 4 个月大时接种 PCV10（3p+0 组）;2 、 4 和 12 个月大时 （2p+1 组）;在 2 个月和 12 个月大时（1p+1 组）;或 12 个月大时（0p+1 组）。从 2016 年到 2020 年，对婴儿（4 至 11 个月大）和幼儿（14 至 24 个月大）进行了年度运输调查。主要终点是防止携带疫苗血清型，在疫苗引入后 3.5 年，与 2p+1 和 3p+0 组相比，在 1p+1 组的非劣效性分析中评估了 3.5 个百分点（非劣效性边际，5 个百分点）。还评估了 0p+1 时间表的非劣效性。结果 2016 年，在引入 PCV10 之前，1363 名婴儿中有 160 名 （11.7%） 发现疫苗血清型携带;2020 年，1p+1、2p+1 和 3p+0 组中 333 名婴儿中有 6 名 （1.8%）、340 名婴儿中有 5 名 （1.5%） 和 313 名婴儿中有 4 名 （1.3%） 发现疫苗血清型携带，表明 1p+1 至 2p+1 的非劣效性（差异，0.3 个百分点;95% 置信区间 [CI]，-1.6 至 2.2）和 3p+0（差异， 0.5 个百分点;95% CI，-1.4 至 2.4）。同样，1p+1 在防止幼儿携带疫苗血清型方面不劣于 2p+1 和 3p+0。2016 年，在 1363 名婴儿中，有 99 名 （7.3%） 发现携带血清型 6A;2020 年，1p+1、2p+1 和 3p+0 组中的 333 名婴儿中有 12 名 （3.6%）、340 名婴儿中有 10 名 （2.9%） 和 313 名婴儿中有 3 名 （1.0%） 被发现。在婴幼儿中，0p+1 方案也不劣于其他三种剂量方案，尽管针对血清型 6A 的交叉保护不如其他疫苗接种方案常见。未观察到 PCV10 相关的严重不良反应。结论 在防止婴幼儿携带疫苗血清型方面，涉及 PCV10 单次基础剂量和加强剂量的减少疫苗接种计划不劣于替代计划。（由比尔和梅琳达·盖茨基金会（Bill and Melinda Gates Foundation）等资助;ClinicalTrials.gov 号，NCT02961231。