Zerbo Ousseny, Modaressi Sharareh, Goddard Kristin, Fireman Bruce, Klein Nicola P
Vaccine Study Center, Kaiser Permanente Northern California, Oakland, and the Department of Health Systems Science, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, California.
Obstet Gynecol. 2025 Jun 26;146(2):e36-e42. doi: 10.1097/AOG.0000000000005986.
To evaluate the effectiveness of influenza vaccination during pregnancy against influenza in infants during their first 6 months of life.
We conducted a cohort study among pregnant individuals enrolled in Kaiser Permanente Northern California (KPNC) and their infants. We followed all infants from birth until the first occurrence of a polymerase chain reaction test result positive for influenza, the infant reached age 6 months, death, disenrollment from KPNC, or the end of the study on December 31, 2022. We used Cox regression to compare the hazard of influenza in infants whose mothers were vaccinated against influenza during pregnancy with those whose mothers were unvaccinated. Hazard ratios (HRs) were adjusted for calendar time, maternal sociodemographic and comorbidities. Vaccine effectiveness was calculated as 100% (1-adjusted HR). We evaluated the association between vaccination and infant influenza outcomes any time during pregnancy and by trimester of vaccination.
Of the 245,498 infants included in the study, 46.0% were born to vaccinated mothers. The incidence of influenza was lower among infants of vaccinated mothers than unvaccinated mothers (0.12% vs 0.30%). After adjusting for covariates, vaccination during pregnancy was associated with a reduction in infant influenza in any clinical setting by 44.4% (95% CI, 31.4-54.9%). Vaccination during the first trimester was associated with a reduction in infant influenza by 11.3%, a reduction of 51.5% during the second trimester, and a reduction of 59.3% during the third trimester. The differences in vaccine effectiveness estimates that compared the first and second trimesters ( P =.02) and compared the first and third trimesters ( P <.001 were statistically significant.
Influenza vaccination during pregnancy was associated with a reduction in infant influenza infection by 44.4%. The reduction in infant influenza infection was greater when vaccination occurred in the second or third trimester, compared with the first trimester.
评估孕期接种流感疫苗对婴儿出生后前6个月患流感的预防效果。
我们对北加利福尼亚凯撒医疗集团（KPNC）登记的孕妇及其婴儿进行了一项队列研究。我们追踪所有婴儿从出生到首次出现流感聚合酶链反应检测结果呈阳性、婴儿满6个月、死亡、退出KPNC或2022年12月31日研究结束。我们使用Cox回归比较母亲在孕期接种流感疫苗的婴儿与未接种疫苗的婴儿患流感的风险。风险比（HRs）根据日历时间、母亲的社会人口统计学特征和合并症进行了调整。疫苗有效性计算为100%（1 - 调整后的HR）。我们评估了孕期任何时间以及按接种孕期进行疫苗接种与婴儿流感结局之间的关联。
在纳入研究的245,498名婴儿中，46.0%的母亲接种了疫苗。接种疫苗母亲的婴儿流感发病率低于未接种疫苗母亲的婴儿（0.12%对0.30%）。在调整协变量后，孕期接种疫苗与任何临床环境下婴儿流感感染率降低44.4%相关（95%CI，31.4 - 54.9%）。孕早期接种疫苗与婴儿流感感染率降低11.3%相关，孕中期降低51.5%，孕晚期降低59.3%。比较孕早期和孕中期（P = 0.02）以及孕早期和孕晚期（P < 0.001）的疫苗有效性估计差异具有统计学意义。
孕期接种流感疫苗与婴儿流感感染率降低44.4%相关。与孕早期相比，孕中期或孕晚期接种疫苗时婴儿流感感染率的降低幅度更大。
