Division of Infectious Diseases, Department of Pediatrics, School of Medicine, Emory University, Atlanta, Georgia, USA.
Emory Vaccine Center, Emory Universitygrid.189967.8grid.471395.dgrid.189967.8 School of Medicine, Atlanta, Georgia, USA.
J Virol. 2022 Sep 14;96(17):e0058222. doi: 10.1128/jvi.00582-22. Epub 2022 Aug 17.
Emerging variants, especially the recent Omicron variant, and gaps in vaccine coverage threaten mRNA vaccine mediated protection against SARS-CoV-2. While children have been relatively spared by the ongoing pandemic, increasing case numbers and hospitalizations are now evident among children. Thus, it is essential to better understand the magnitude and breadth of vaccine-induced immunity in children against circulating viral variant of concerns (VOCs). Here, we compared the magnitude and breadth of humoral immune responses in adolescents and adults 1 month after the two-dose Pfizer (BNT162b2) vaccination. We found that adolescents (aged 11 to 16) demonstrated more robust binding antibody and neutralization responses against the wild-type SARS-CoV-2 virus spike protein contained in the vaccine compared to adults (aged 27 to 55). The quality of the antibody responses against VOCs in adolescents were very similar to adults, with modest changes in binding and neutralization of Beta, Gamma, and Delta variants. In comparison, a significant reduction of binding titers and a striking lack of neutralization was observed against the newly emerging Omicron variant for both adolescents and adults. Overall, our data show that a two-dose BNT162b2 vaccine series may be insufficient to protect against the Omicron variant. While plasma binding and neutralizing antibody responses have been reported for cohorts of infected and vaccinated adults, much less is known about the vaccine-induced antibody responses to variants including Omicron in children. This illustrates the need to characterize vaccine efficacy in key vulnerable populations. A third (booster) dose of BNTb162b was approved for children 12 to 15 years of age by the Food and Drug Administration (FDA) on January 1, 2022, and pediatric clinical trials are under way to evaluate the safety, immunogenicity, and effectiveness of a third dose in younger children. Similarly, variant-specific booster doses and pan-coronavirus vaccines are areas of active research. Our data show adolescents mounted stronger humoral immune responses after vaccination than adults. It also highlights the need for future studies of antibody durability in adolescents and children as well as the need for future studies of booster vaccination and their efficacy against the Omicron variant.
新兴变体，尤其是最近的奥密克戎变体，以及疫苗接种覆盖率的差距，威胁着 mRNA 疫苗对 SARS-CoV-2 的保护作用。虽然儿童在持续的大流行中相对幸免，但现在儿童中的病例数和住院人数正在增加。因此，必须更好地了解儿童对流行病毒变体（VOCs）的疫苗诱导免疫的程度和广度。在这里，我们比较了青少年和成年人在接受两剂辉瑞（BNT162b2）疫苗接种后一个月的体液免疫反应的程度和广度。我们发现，与成年人（27 至 55 岁）相比，青少年（11 至 16 岁）对疫苗中包含的野生型 SARS-CoV-2 病毒刺突蛋白表现出更强大的结合抗体和中和反应。青少年对 VOCs 的抗体反应质量与成年人非常相似，对 Beta、Gamma 和 Delta 变体的结合和中和反应略有变化。相比之下，青少年和成年人对新出现的奥密克戎变体的结合滴度显著降低，并且缺乏中和作用。总的来说，我们的数据表明，两剂 BNT162b2 疫苗系列可能不足以预防奥密克戎变体。虽然已经报道了针对感染和接种疫苗的成年人队列的血浆结合和中和抗体反应，但对包括奥密克戎在内的变体在儿童中的疫苗诱导抗体反应知之甚少。这说明了需要在关键弱势群体中描述疫苗的功效。食品和药物管理局（FDA）于 2022 年 1 月 1 日批准为 12 至 15 岁的儿童接种第三剂（加强针）BNTb162b，儿科临床试验正在进行中，以评估在年幼儿童中接种第三剂的安全性、免疫原性和有效性。同样，针对变体的特异性加强针剂量和泛冠状病毒疫苗是当前研究的重点。我们的数据表明，青少年接种疫苗后的体液免疫反应比成年人更强。它还强调了未来研究青少年和儿童抗体持久性的必要性，以及未来研究加强针接种及其对奥密克戎变体的功效的必要性。
