Live-attenuated chikungunya vaccine in children: a randomized phase 2 trial.

In this phase 2, observer-blind, randomized, dose-response trial we evaluated the tolerability (solicited adverse events (AEs)), safety (unsolicited AEs) and immunogenicity of a live-attenuated CHIKV vaccine (VLA1553) in healthy children aged 1-11 years in endemic countries.

在这项2期、观察者盲法、随机、剂量反应试验中，我们评估了活病毒减毒基孔肯雅病毒疫苗（VLA1553）在流行国家1至11岁健康儿童中的耐受性（诱导的不良事件（AEs））、安全性（非诱导的不良事件）和免疫原性。

Here we provide a prespecified interim analysis to 28 days after vaccination.

在此我们提供了疫苗接种后28天的预先设定的中期分析。

Participants (n = 304) received either a half dose (n = 119) or a full dose (n = 124) of VLA1553, or active control meningococcal vaccine (Nimenrix) (n = 61).

参与者（n = 304）接受了VLA1553的半剂量（n = 119）或全剂量（n = 124），或者活性对照脑膜炎疫苗（Nimenrix）（n = 61）。

The primary endpoint was the incidenceand severity of solicited AEs within 14 days after vaccination.

主要终点是接种疫苗后14天内所发生的和严重程度的主动报告不良事件。

Secondary endpoints included unsolicited AEs, medically attended AEs, serious AEs, AEs of special interest and immunogenicity through 28 days after vaccination.

次要终点包括接种疫苗后28天内的非主动报告不良事件、需医疗关注的不良事件、严重不良事件、特殊关注的不良事件以及免疫原性。

For the primary endpoint, there were no statistically significant differences between the VLA1553 groups and control for each age group nor between age groups (1-2, 3-6 and 7-11 years).

对于主要终点，VLA1553组与对照组在每个年龄组之间以及年龄组之间（1-2岁、3-6岁和7-11岁）均无统计学显著性差异。

Overall, the most frequently reported solicited injection site AEs were tenderness (10.9%) and pain (8.6% of participants); the most frequently reported solicited systemic AEs were fever (12.5%) and headache (11.5%; participants aged 7-11 years and 3-6 years only, (headache was not solicited in participants aged 1-2 years)).

总体而言，最常见的主动报告的注射部位不良事件是触痛（10.9%）和疼痛（8.6%的参与者）；最常见的主动报告的全身不良事件是发热（12.5%）和头痛（11.5%；仅限于7-11岁和3-6岁的参与者，（1-2岁的参与者中未主动报告头痛）。

For the secondary safety endpoints, the most common unsolicited AEs were infections and infestations (10.0-20.5%) and the most common medically attended AE overall was fever (2.6%), with no differences for unsolicited AEs or medically attended AEs regardless of vaccine and age group (serious AEs and AEs of special interest were too infrequent for meaningful comparisons).

对于次要安全终点，最常见的非计划不良事件是感染和寄生虫病（10.0-20.5%），最常见的需要医疗关注的不良事件总体上是发热（2.6%），无论疫苗种类还是年龄组，非计划不良事件或需要医疗关注的不良事件均无差异（严重不良事件和特殊关注的不良事件发生率过低，无法进行有意义的比较）。

Anti-CHIKV neutralizing antibody titers were higher in the full-dose than the half-dose group at days 14 and 28 after vaccination.

在接种疫苗后的第14天和第28天，全剂量组的抗CHIKV中和抗体滴度高于半剂量组。

The trial met its prespecified endpoints and supported the selection of full-dose VLA1553 in future clinical trials in this population, addressing a critical unmet medical need.

该试验达到了预先设定的终点，并支持在未来的临床试验中为这一人群选择全剂量VLA1553，解决了一个关键的未满足的医疗需求。

ClinicalTrials.gov registration: NCT06106581 .

ClinicalTrials.gov注册号：NCT06106581。