Zhong Jiayi, Wang Wen, Liu Shuang, Chen Yifei, Xiong Husheng, Meng Xiang, Zhang Dingmei, Ma Yu
Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou 510080, China.
Institute of Public Health, Guangzhou Medical University & Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China.
Vaccines (Basel). 2023 Aug 22;11(9):1402. doi: 10.3390/vaccines11091402.
This study aims to evaluate the effectiveness of maternal inactivated COVID-19 vaccination before delivery for infants against Omicron infection in Guangzhou, China. A test-negative case-control design was conducted. This study selected infants born from 1 November 2021 to 23 November 2022 and tested for SARS-CoV-2 between 13 April 2022 and 30 November 2022 during outbreaks in Guangzhou. Multivariable logistic regression was performed to compare the maternal vaccination status of inactivated COVID-19 vaccines before delivery in cases and controls to estimate vaccine effectiveness (VE) for infants within 12 months. According to eligibility criteria, we finally selected 205 test-positive and 114 test-negative infants, as well as their mothers. The effectiveness of inactivated COVID-19 vaccines among fully vaccinated mothers was 48.4% (7.3% to 71.7%) for infants within 12 months, with the effectiveness of partial and booster vaccination showing no significant difference. Effectiveness for full vaccination presented a slight increase according to infants' age at testing, with 49.6% (-12.3% to 78.4%) for 0-6 months and 59.9% (-0.6% to 84.4%) for over 6 months. A greater protective effect of two-dose vaccination was manifested in infants whose mother had received the second dose during the first trimester (65.9%, 95% CI: 7.7% to 87.9%) of pregnancy rather than preconception (43.5%, 95% CI: -8.7% to 71.1%). Moreover, VE could be improved to 77.1% (11.1% to 95.3%) when mothers received two doses both during pregnancy and 91.8% (41.1% to 99.6%) with receipt of a booster dose during pregnancy. Maternal vaccination with two doses of inactivated COVID-19 vaccines before delivery was moderately effective against Omicron infection in infants during the first 12 months of life. Full vaccination or a booster dose during pregnancy could confer better protection against Omicron for infants, although it might be overestimated due to the insufficient sample size in subgroups.
本研究旨在评估中国广州地区产妇在分娩前接种新冠病毒灭活疫苗对婴儿预防奥密克戎感染的有效性。采用了检测阴性病例对照设计。本研究选取了2021年11月1日至2022年11月23日出生、并在2022年4月13日至11月30日广州疫情期间接受新冠病毒检测的婴儿。进行多变量逻辑回归分析，以比较病例组和对照组中产妇在分娩前接种新冠病毒灭活疫苗的情况，从而估算12个月内婴儿的疫苗有效性（VE）。根据纳入标准，我们最终选取了205名检测呈阳性的婴儿、114名检测呈阴性的婴儿及其母亲。在完全接种疫苗的母亲中，新冠病毒灭活疫苗对12个月内婴儿的有效性为48.4%（7.3%至71.7%），部分接种和加强接种的有效性无显著差异。根据检测时婴儿的年龄，完全接种的有效性略有增加，0至6个月婴儿为49.6%（-12.3%至78.4%），6个月以上婴儿为59.9%（-0.6%至84.4%）。母亲在孕早期（孕期前三个月）而非孕前接种第二剂疫苗时，两剂疫苗对婴儿的保护作用更强（65.9%，95%置信区间：7.7%至87.9%），而非孕前接种时为43.5%（95%置信区间：-8.7%至71.1%）。此外，母亲在孕期接种两剂疫苗时，疫苗有效性可提高至77.1%（11.1%至95.3%）；孕期接种加强剂时，有效性可达91.8%（41.1%至99.6%）。产妇在分娩前接种两剂新冠病毒灭活疫苗对婴儿出生后前12个月预防奥密克戎感染有一定效果。孕期完全接种或接种加强剂可为婴儿提供更好的奥密克戎防护，不过由于亚组样本量不足，可能存在高估情况。
