Substantial immunological changes occur throughout pregnancy to render the mother immunologically tolerant to the fetus and allow fetal growth. However, additional local and systemic immunological adaptations also occur, allowing the maternal immune system to continue to protect the dyad against pathogens both during pregnancy and after birth through lactation. This fine balance of tolerance and immunity, along with physiological and hormonal changes, contributes to increased susceptibility to particular infections in pregnancy, including more severe coronavirus disease 2019 (COVID-19). Whether these changes also make pregnant women less responsive to vaccination or induce altered immune responses to vaccination remains incompletely understood. To define potential changes in vaccine response during pregnancy and lactation, we undertook deep sequencing of the humoral vaccine response in a group of pregnant and lactating women and nonpregnant age-matched controls. Vaccine-specific titers were comparable between pregnant women, lactating women, and nonpregnant controls. However, Fc receptor (FcR) binding and antibody effector functions were induced with delayed kinetics in both pregnant and lactating women compared with nonpregnant women after the first vaccine dose, which normalized after the second dose. Vaccine boosting resulted in high FcR-binding titers in breastmilk. These data suggest that pregnancy promotes resistance to generating proinflammatory antibodies and indicates that there is a critical need to follow prime-boost timelines in this vulnerable population to ensure full immunity is attained.

中文翻译：

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COVID-19 mRNA 疫苗在孕妇、哺乳期和非孕妇中驱动差异抗体 Fc 功能谱

整个孕期都会发生显着的免疫学变化，从而使母亲对胎儿产生免疫耐受性并允许胎儿生长。然而，额外的局部和全身免疫适应也会发生，使母体免疫系统在怀孕期间和出生后通过哺乳期继续保护二元体免受病原体的侵害。这种耐受性和免疫的良好平衡，以及生理和荷尔蒙的变化，有助于增加怀孕期间对特定感染的易感性，包括更严重的 2019 年冠状病毒病 (COVID-19)。这些变化是否也会使孕妇对疫苗接种的反应降低或诱导对疫苗接种的免疫反应改变仍然不完全清楚。为了确定怀孕和哺乳期间疫苗反应的潜在变化，我们对一组孕妇和哺乳期妇女以及未怀孕的年龄匹配对照组的体液疫苗反应进行了深度测序。孕妇、哺乳期妇女和非怀孕对照之间的疫苗特异性滴度具有可比性。然而，与非孕妇相比，在第一次接种疫苗后，孕妇和哺乳期妇女的 Fc 受体 (FcR) 结合和抗体效应功能被诱导，动力学延迟，第二次接种后恢复正常。疫苗加强导致母乳中的高 FcR 结合滴度。这些数据表明，怀孕会促进对产生促炎抗体的抵抗力，并表明迫切需要在这个易受伤害的人群中遵循初始增强时间线，以确保获得完全免疫。