Minimal mRNA uptake and inflammatory response to COVID-19 mRNA vaccine exposure in human placental explants

Veronica J Gonzalez; Lin Li; Sirirak Buarpung; Mary Prahl; Joshua F Robinson; Stephanie L Gaw

doi:10.1016/j.isci.2023.107549

Minimal mRNA uptake and inflammatory response to COVID-19 mRNA vaccine exposure in human placental explants

iScience. 2023 Aug 7;26(9):107549. doi: 10.1016/j.isci.2023.107549. eCollection 2023 Sep 15.

Authors

Veronica J Gonzalez¹, Lin Li^{1

2}, Sirirak Buarpung¹, Mary Prahl³, Joshua F Robinson², Stephanie L Gaw^{1

2}

Affiliations

¹ Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, San Francisco, CA 94158, USA.
² Center for Reproductive Sciences, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, San Francisco, CA 94143, USA.
³ Division of Pediatric Infectious Diseases and Global Health, Department of Pediatrics, University of California, San Francisco, San Francisco, CA 94110, USA.

Abstract

Despite universal recommendations for COVID-19 mRNA vaccination in pregnancy, uptake has been lower than desired. There have been limited studies of the direct impact of COVID-19 mRNA vaccine exposure in human placental tissue. Using a primary human placental explants model, we investigated the uptake of two common mRNA vaccines (BNT162b2 Pfizer-BioNTech or mRNA-1273 Moderna), and whether exposure altered villous cytokine responses. Explants derived from second or third trimester chorionic villi were incubated with vaccines at supraphysiologic concentrations and analyzed at two time points. We observed minimal uptake of mRNA vaccines in placental explants by in situ hybridization and quantitative RT-PCR. No specific or global cytokine response was elicited by either of the mRNA vaccines in multiplexed immunoassays. Our results suggest that the human placenta does not readily absorb the COVID-19 mRNA vaccines nor generate a significant inflammatory response after exposure.

Keywords: Biological sciences; Immune response; Immunology; Microbiology.

Abstract

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