Yang Xiaoqi, Fox Alisa, DeCarlo Claire, Pineda Nicole, Powell Rebecca L R
Division of Infectious Diseases, Department of Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, New York, USA.
medRxiv. 2023 May 26:2023.05.19.23290192. doi: 10.1101/2023.05.19.23290192.
Although in the early pandemic period, COVID-19 pathology among young children and infants was typically less severe compared to that observed among adults, this has not remained entirely consistent as SARS-CoV-2 variants have emerged. There is an enormous body of evidence demonstrating the benefits of human milk antibodies (Abs) in protecting infants against a wide range of enteric and respiratory infections. It is highly plausible that the same holds true for protection against SARS-CoV-2, as this virus infects cells of the gastrointestinal and respiratory mucosae. Understanding the durability of a human milk Ab response over time after infection is critical. Previously, we examined the Abs present in milk of those recently infected with SARS-CoV-2, and concluded that the response was secretory IgA (sIgA)-dominant and that these titers were highly correlated with neutralization potency. The present study aimed to monitor the durability of the SARS-CoV-2 IgA and secretory Ab (sAb) response in milk from COVID-19-recovered lactating individuals over 12 months, in the absence of vaccination or re-infection. This analysis revealed a robust and durable Spike-specific milk sIgA response, that at 9-12 months after infection, 88% of the samples exhibited titers above the positive cutoff for IgA and 94% were above cutoff for sAb. Fifty percent of participants exhibited less than a 2-fold reduction of Spike-specific IgA through 12 months. A strong significant positive correlation between IgA and sAb against Spike persisted throughout the study period. Nucleocapsid-specific Abs were also assessed, which revealed significant background or cross reactivity of milk IgA against this immunogen, as well as limited/inconsistent durability compared to Spike titers. These data suggests that lactating individuals are likely to continue producing Spike-specific Abs in their milk for 1 year or more, which may provide critical passive immunity to infants against SARS-CoV-2 throughout the lactation period.
尽管在疫情早期，与成人相比，幼儿和婴儿的新冠病毒病理学表现通常不那么严重，但随着新冠病毒变异株的出现，情况并非完全如此。有大量证据表明，母乳抗体（Abs）在保护婴儿免受多种肠道和呼吸道感染方面具有益处。鉴于这种病毒感染胃肠道和呼吸道黏膜细胞，母乳抗体对新冠病毒的保护作用极有可能同样成立。了解感染后母乳抗体反应随时间的持续时间至关重要。此前，我们检测了近期感染新冠病毒者乳汁中的抗体，得出的结论是，该反应以分泌型IgA（sIgA）为主，且这些滴度与中和效力高度相关。本研究旨在监测新冠康复哺乳期个体乳汁中新冠病毒IgA和分泌型抗体（sAb）反应在12个月内的持续时间，期间未接种疫苗或再次感染。该分析揭示了一种强大且持久的针对刺突蛋白的乳汁sIgA反应，即在感染后9至12个月，88%的样本IgA滴度高于阳性临界值，94%的样本sAb滴度高于临界值。50%的参与者在12个月内针对刺突蛋白的IgA滴度降低不到2倍。在整个研究期间，针对刺突蛋白的IgA和sAb之间始终存在强烈的显著正相关。还评估了针对核衣壳的抗体，结果显示乳汁IgA针对该免疫原存在显著的背景或交叉反应，且与刺突蛋白滴度相比，其持续时间有限/不一致。这些数据表明，哺乳期个体可能会在乳汁中持续产生针对刺突蛋白的抗体达1年或更长时间，这可能在整个哺乳期为婴儿提供针对新冠病毒的关键被动免疫。
