Background

The incidence of coronavirus disease 2019 (Covid-19) among adolescents between 12 and 17 years of age was approximately 900 per 100,000 population from April 1 through June 11, 2021. The safety, immunogenicity, and efficacy of the mRNA-1273 vaccine in adolescents are unknown.

Methods

In this ongoing phase 2–3, placebo-controlled trial, we randomly assigned healthy adolescents (12 to 17 years of age) in a 2:1 ratio to receive two injections of the mRNA-1273 vaccine (100 μg in each) or placebo, administered 28 days apart. The primary objectives were evaluation of the safety of mRNA-1273 in adolescents and the noninferiority of the immune response in adolescents as compared with that in young adults (18 to 25 years of age) in a phase 3 trial. Secondary objectives included the efficacy of mRNA-1273 in preventing Covid-19 or asymptomatic severe acute respiratory syndrome coronavirus 2 infection.

Results

A total of 3732 participants were randomly assigned to receive mRNA-1273 (2489 participants) or placebo (1243 participants). In the mRNA-1273 group, the most common solicited adverse reactions after the first or second injections were injection-site pain (in 93.1% and 92.4%, respectively), headache (in 44.6% and 70.2%, respectively), and fatigue (in 47.9% and 67.8%, respectively); in the placebo group, the most common solicited adverse reactions after the first or second injections were injection-site pain (in 34.8% or 30.3%, respectively), headache (in 38.5% and 30.2%, respectively), and fatigue (in 36.6% and 28.9%, respectively). No serious adverse events related to mRNA-1273 or placebo were noted. The geometric mean titer ratio of pseudovirus neutralizing antibody titers in adolescents relative to young adults was 1.08 (95% confidence interval [CI], 0.94 to 1.24), and the absolute difference in serologic response was 0.2 percentage points (95% CI, −1.8 to 2.4), which met the noninferiority criterion. No cases of Covid-19 with an onset of 14 days after the second injection were reported in the mRNA-1273 group, and four cases occurred in the placebo group.

Conclusions

The mRNA-1273 vaccine had an acceptable safety profile in adolescents. The immune response was similar to that in young adults, and the vaccine was efficacious in preventing Covid-19. (Funded by Moderna and the Biomedical Advanced Research and Development Authority; Teen COVE ClinicalTrials.gov number, NCT04649151.)

中文翻译：

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mRNA-1273 SARS-CoV-2 疫苗在青少年中的评估

背景

从 2021 年 4 月 1 日到 6 月 11 日，12 至 17 岁青少年冠状病毒病 2019（Covid-19）的发病率约为每 100,000 人 900 人。 mRNA-1273 疫苗在青少年中的安全性、免疫原性和有效性是未知的。

方法

在这项正在进行的 2-3 期安慰剂对照试验中，我们以 2:1 的比例随机分配健康青少年（12 至 17 岁）接受两次 mRNA-1273 疫苗（每次 100 μg）或安慰剂注射，相隔 28 天给药。主要目标是在 3 期试验中评估 mRNA-1273 在青少年中的安全性以及青少年免疫反应与年轻成人（18 至 25 岁）相比的非劣效性。次要目标包括 mRNA-1273 在预防 Covid-19 或无症状严重急性呼吸系统综合症冠状病毒 2 感染方面的功效。

结果

共有 3732 名参与者被随机分配接受 mRNA-1273（2489 名参与者）或安慰剂（1243 名参与者）。在 mRNA-1273 组中，第一次或第二次注射后最常见的不良反应是注射部位疼痛（分别为 93.1% 和 92.4%）、头痛（分别为 44.6% 和 70.2%）和疲劳（分别为 47.9% 和 67.8%）；在安慰剂组中，第一次或第二次注射后最常见的不良反应是注射部位疼痛（分别为 34.8% 或 30.3%）、头痛（分别为 38.5% 和 30.2%）和疲劳（分别为 36.6%） % 和 28.9%）。未发现与 mRNA-1273 或安慰剂相关的严重不良事件。青少年假病毒中和抗体滴度相对于青年人的几何平均滴度比为 1。08（95% CI，0.94～1.24），血清学反应的绝对差异为0.2个百分点（95% CI，-1.8～2.4），符合非劣效性标准。在 mRNA-1273 组中没有报告在第二次注射后 14 天发病的 Covid-19 病例，安慰剂组发生了 4 例。

结论

mRNA-1273 疫苗在青少年中具有可接受的安全性。免疫反应与年轻人相似，疫苗可有效预防 Covid-19。（由 Moderna 和生物医学高级研究与发展局资助；Teen COVE ClinicalTrials.gov 编号，NCT04649151。）