Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
Public Health Ontario, Toronto, Ontario, Canada.
PLoS One. 2023 Mar 31;18(3):e0283715. doi: 10.1371/journal.pone.0283715. eCollection 2023.
Vaccines against SARS-CoV-2 have been shown to reduce risk of infection as well as severe disease among those with breakthrough infection in adults. The latter effect is particularly important as immune evasion by Omicron variants appears to have made vaccines less effective at preventing infection. Therefore, we aimed to quantify the protection conferred by mRNA vaccination against hospitalization due to SARS-CoV-2 in adolescent and pediatric populations.
We retrospectively created a cohort of reported SARS-CoV-2 case records from Ontario's Public Health Case and Contact Management Solution among those aged 4 to 17 linked to vaccination records from the COVaxON database on January 19, 2022. We used multivariable logistic regression to estimate the association between vaccination and hospitalization among SARS-CoV-2 cases prior to and during the emergence of Omicron.
We included 62 hospitalized and 27,674 non-hospitalized SARS-CoV-2 cases, with disease onset from May 28, 2021 to December 4, 2021 (Pre-Omicron) and from December 23, 2021 to January 9, 2022 (Omicron). Among adolescents, two mRNA vaccine doses were associated with an 85% (aOR = 0.15; 95% CI: [0.04, 0.53]; p<0.01) lower likelihood of hospitalization among SARS-CoV-2 cases caused by Omicron. Among children, one mRNA vaccine dose was associated with a 79% (aOR = 0.21; 95% CI: [0.03, 0.77]; p<0.05) lower likelihood of hospitalization among SARS-CoV-2 cases caused by Omicron. The calculation of E-values, which quantifies how strong an unmeasured confounder would need to be to nullify our findings, suggest that these effects are unlikely to be explained by unmeasured confounding.
Despite immune evasion by SARS-CoV-2 variants, vaccination continues to be associated with a lower likelihood of hospitalization among adolescent and pediatric Omicron (B.1.1.529) SARS-CoV-2 cases, even when the vaccines do not prevent infection. Continued efforts are needed to increase vaccine uptake among adolescent and pediatric populations.
已证实，在成年人中，SARS-CoV-2 疫苗可降低突破性感染的风险，包括严重疾病风险。后一种效果尤为重要，因为奥密克戎变异体的免疫逃逸似乎使疫苗在预防感染方面的效果降低。因此，我们旨在量化 mRNA 疫苗在预防青少年和儿科人群因 SARS-CoV-2 住院方面的保护作用。
我们在 2022 年 1 月 19 日从安大略省公共卫生病例和联系人管理解决方案中回顾性地创建了一个 SARS-CoV-2 病例报告队列，该队列来自于年龄在 4 至 17 岁的人群，并与 COVaxON 数据库中的疫苗接种记录相关联。我们使用多变量逻辑回归来估计奥密克戎出现之前和期间，疫苗接种与 SARS-CoV-2 病例住院之间的关联。
我们纳入了 62 例住院和 27674 例非住院 SARS-CoV-2 病例，发病时间为 2021 年 5 月 28 日至 2021 年 12 月 4 日（奥密克戎前）和 2021 年 12 月 23 日至 2022 年 1 月 9 日（奥密克戎期间）。在青少年中，两剂 mRNA 疫苗与奥密克戎引起的 SARS-CoV-2 病例住院的可能性降低 85%相关（调整后的比值比[aOR] = 0.15；95%置信区间[CI]：[0.04，0.53]；p<0.01）。在儿童中，一剂 mRNA 疫苗与奥密克戎引起的 SARS-CoV-2 病例住院的可能性降低 79%相关（aOR = 0.21；95%CI：[0.03，0.77]；p<0.05）。计算效应值（E 值），这可以量化未测量的混杂因素需要有多强才能使我们的发现无效，结果表明，这些影响不太可能是由未测量的混杂因素引起的。
尽管 SARS-CoV-2 变异体存在免疫逃逸，但疫苗接种与青少年和儿科人群的奥密克戎（B.1.1.529）SARS-CoV-2 病例住院的可能性降低仍然相关，即使疫苗不能预防感染。需要继续努力提高青少年和儿科人群的疫苗接种率。
