key: cord-0825375-2dd3ivz7 authors: Prahl, M.; Golan, Y.; Cassidy, A. G.; Matsui, Y.; Li, L.; Alvarenga, B.; Chen, H.; Jigmeddagva, U.; Lin, C. Y.; Gonzalez, V. J.; Chidboy, M. A.; Warrier, L.; Buarpung, S.; Murtha, A. P.; Flaherman, V. J.; Greene, W. C.; Wu, A. H. B.; Lynch, K. L.; Rajan, J.; Gaw, S. L. title: Evaluation of transplacental transfer of mRNA vaccine products and functional antibodies during pregnancy and early infancy date: 2021-12-13 journal: medRxiv : the preprint server for health sciences DOI: 10.1101/2021.12.09.21267423 sha: 8bbe07c13fb7274accbcc4072272e6df0f92b474 doc_id: 825375 cord_uid: 2dd3ivz7 Studies are needed to evaluate the safety and effectiveness of mRNA SARS-CoV-2 vaccination during pregnancy, and the levels of protection provided to their newborns through placental transfer of antibodies. We evaluated the transplacental transfer of mRNA vaccine products and functional anti-SARS-CoV-2 antibodies during pregnancy and early infancy in a cohort of 20 individuals vaccinated during pregnancy. We found no evidence of mRNA vaccine products in maternal blood, placenta tissue, or cord blood at delivery. However, we found time-dependent efficient transfer of IgG and neutralizing antibodies to the neonate that persisted during early infancy. Additionally, using phage immunoprecipitation sequencing, we found a vaccine-specific signature of SARS-CoV-2 Spike protein epitope binding that is transplacentally transferred during pregnancy. In conclusion, products of mRNA vaccines are not transferred to the fetus during pregnancy, however timing of vaccination during pregnancy is critical to ensure transplacental transfer of protective antibodies during early infancy. 3 effects on the embryo or fetus, even with strong consensus recommendations for COVID-19 53 vaccination prior to or during pregnancy from several medical societies 6 . Pregnant individuals 54 were excluded from initial vaccine trials, and complete data on safety, efficacy, optimal timing of 55 the vaccine in pregnancy, or its impact on the fetus has been delayed 7 , which may impact 56 individual medical decision making. Current COVID-19 vaccines fully approved and under 57 emergency use in the United States include the mRNA vaccines BNT-162b2 and mRNA-1273, 58 which target the SARS-CoV-2 Spike protein and stimulate protective immune responses 8, 9 . In 59 addition to protecting the mother against severe disease, vaccination during pregnancy may One participant who was vaccinated at 13 weeks had a termination of pregnancy due to a lethal 77 skeletal dysplasia of genetic etiology at 20.4 weeks. Eight participants received BNT-162b2 78 All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted December 13, 2021. ; https://doi.org/10.1101/2021.12.09.21267423 doi: medRxiv preprint 4 (Pfizer-BioNTech) and twelve received mRNA-1273 (Moderna) vaccines. Eighteen participants 79 received both vaccine doses prior to delivery, and two participants received the second dose 80 after delivery. The time from first mRNA vaccine dose ranged from 6-97 (mean 51, SD 24.3) 81 days prior to delivery, time from the second dose ranged from 2-75 (mean 32, SD 21.3) days 82 prior to delivery, and in two participants 15 and 21 days after delivery. No participants received 83 a 3 rd dose prior to delivery. Infants born to vaccinated mothers were followed up at convenience 84 time points ranging from age 3 weeks to 15 weeks of life (mean 8.3, SD 3.2). Further 85 demographic data is detailed in Table S1 . Vaccine mRNA products do not cross the placenta To determine the transplacental transfer of mRNA vaccine derived products, we 89 examined available maternal blood at delivery, placenta tissue, and cord blood for Spike protein 90 by Western blot and vaccine mRNA by PCR. All available delivery samples (maternal blood, 91 placental tissue, and cord blood) were negative for Spike protein by Western blot (Supp Figure 92 1, Supp Table 3 ) and did not have detectable levels of vaccine mRNA by PCR (Suppl Table 3 ). Together, this indicates that products of mRNA vaccination do not reach the fetus after 94 vaccination during pregnancy at readily detectable levels. 95 96 mRNA vaccination in pregnancy leads to a robust antibody response 97 Similar to prior studies 14,15,17 , we found that mRNA vaccination during pregnancy led to 98 an increase in anti-SARS-Cov-2 IgG following dose 1 (n=7, mean 388.6, SD 224.8 RFU) and an 99 even further robust increase after vaccination dose 2 (n=12, mean 3214, SD 1383 RFU). Anti-100 SARS-CoV-2 IgM (n=7, mean 53.3, SD 50.2 RFU) was detected in two maternal participants 101 following dose 1, but only 1 participant following dose 2 (n=12, mean 23.8, SD 17 RFU, Fig 1) . All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. 110 RFU). One participant received one mRNA vaccine dose 9 days prior to delivery, and both the 111 maternal and cord blood were negative for IgG at the time of delivery. Another participant 112 received two doses of mRNA vaccine (23 and 2 days) prior to delivery and maternal blood was 113 positive at 55 RFU (positive cutoff >50 RFU), however cord blood IgG was negative ( Figure 2A ). Maternal and cord blood anti-SARS-CoV-2 IgG levels were moderately correlated, but not 115 statistically significant (p=0.074, Rs=0.446, Fig 2A) . All cord blood samples were anti-SARS- CoV-2 IgM negative. We next evaluated the transplacental transfer of neutralizing antibody titers by a label-118 free surrogate neutralization assay (sVNT) from mother to cord blood. Maternal and cord blood 119 at delivery had robust neutralizing responses (maternal n=17, mean 220.2, range [0, 422]. Cord 120 blood n=16, mean 296.6, range [0, 485], Fig 2B) . All mother-infant dyads with positive IgG 121 serology at delivery had detectable transplacental transfer of neutralizing antibodies with the 122 exception of one pair in which the mother was borderline IgG positive at delivery and cord blood 123 was negative, for which both maternal and cord blood were negative for neutralizing titers (Fig 124 2B ). However, maternal and cord blood neutralizing titers were not significantly correlated 125 (p=0.361, Rs=-0.244, Fig 2B) . Taken together, this indicates that maternal mRNA vaccination 126 induces functional neutralizing antibodies that are transferred to the infant. 128 All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. Fig 2A) , with one 133 infant still IgG positive at 12 weeks of age ( Fig 2C) . The two infants that were IgG negative at 134 follow up were both born to mothers who received only one vaccine dose prior to delivery (6 and 135 9 days, respectively). One of these infants did not have paired maternal or cord blood available preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. We assessed the relationship of anti-SARS-CoV-2 IgG levels to neutralizing antibody 154 levels. We found a strong correlation between IgG and neutralizing titers in maternal plasma at 155 delivery (Rs=0.744, p=0.0012) and infant follow up (Rs=0.738, p=0.046) timepoints, but no 156 significant association between IgG and neutralizing titers in cord blood (Rs=0.121, p=0.656, 157 Figure 3 ). We then evaluated the impact of timing of vaccination on maternal antibody levels at 159 delivery. We found no statistically significant correlation between maternal IgG levels at delivery To assess facilitated antibody transfer, we evaluated cord-to-maternal antibody IgG and 170 neutralization titer ratios by time since vaccination and gestational age. We found that IgG ratios 171 were highly correlated with both time since first maternal vaccination dose and gestational age 179 All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted December 13, 2021. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted December 13, 2021. ; https://doi.org/10.1101/2021.12.09.21267423 doi: medRxiv preprint 9 Among twenty women who received the COVID-19 mRNA vaccine during pregnancy, 206 our study found no evidence of transplacental transfer of mRNA vaccine products but did find 207 high levels of functional vaccine-derived antibodies that transferred to the infant at delivery and 208 persisted during early infancy. Additionally, we identified high levels of epitope binding in two 209 regions of Spike protein unique to SARS-CoV-2 vaccination 18 . These data may address some of We found that the timing of immunization during pregnancy is important to ensure trans- preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. were not transferred in a mother who received her second dose of vaccine 2 days prior to 232 delivery. All evaluated mothers who received both doses during pregnancy and with the second 233 dose greater than 9 days prior to delivery transferred IgG and neutralizing antibodies to their Consistent with observations in non-pregnant adults, we found that IgG levels in mothers 255 at delivery, and at infant follow-up were highly correlated with neutralizing titers 28 . However, 256 cord blood IgG levels did not correlate with neutralizing titers. Moreover, IgG cord-to-maternal 257 All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted December 13, 2021. ; https://doi.org/10.1101/2021.12.09.21267423 doi: medRxiv preprint ratios, which represent a proxy of maternal to fetal antibody transfer, were highly correlated with 258 timing of vaccination (gestational age and days since the first dose), but cord-to-maternal 259 neutralizing titer ratios were not significantly associated with time since vaccination nor 283 All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The calculated p values were corrected for multiple hypothesis using the Benjamini-Hochberg 387 All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted December 13, 2021. ; https://doi.org/10.1101/2021.12.09.21267423 doi: medRxiv preprint 21 delivery (n=17), cord plasma (n=16), and infant follow-up (n=8) by SARS-CoV-2 label-free preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. F. All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted December 13, 2021. ; https://doi.org/10.1101/2021.12.09.21267423 doi: medRxiv preprint 24 antibody transfer ratio by gestational age at vaccine dose 1 (n=15 preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted December 13, 2021. ; https://doi.org/10.1101/2021.12.09.21267423 doi: medRxiv preprint preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted December 13, 2021. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted December 13, 2021. ; https://doi.org/10.1101/2021.12.09.21267423 doi: medRxiv preprint Characteristics of Women of Reproductive Age with Laboratory-594 Confirmed SARS-CoV-2 Infection by Pregnancy Status -United States Association of SARS-CoV-2 Test Status and Pregnancy Outcomes Characteristics and outcomes of pregnant women admitted to hospital 600 with confirmed SARS-CoV-2 infection in UK: national population based cohort study Pregnant women with SARS-CoV-2 infection are at higher 603 risk of death and pneumonia: propensity score matched analysis of a nationwide 604 prospective cohort (COV19Mx) COVID-19 vaccination among pregnant people aged 18-49 years overall, by 607 race/ethnicity, and date reported to CDC -Vaccine Safety Datalink,* United States Statement of Strong Medical Consensus for Vaccination of 610 Pregnant Individuals Against COVID-19 Health Policy Advocacy, C. Pregnant people deserve the protection offered by SARS CoV-2 vaccines An mRNA Vaccine against SARS-CoV-2 -Preliminary Report Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine Compromised SARS-CoV-2-specific placental antibody transfer Assessment of Maternal and Neonatal SARS-CoV-2 Viral Load Transplacental Antibody Transfer, and Placental Pathology in Pregnancies During the 624 COVID-19 Pandemic Compromised SARS-CoV-2-specific placental antibody transfer Coronavirus disease 2019 vaccine response in pregnant and lactating 632 women: a cohort study Maternal-neonatal transfer of SARS-CoV-2 immunoglobulin G antibodies 635 among parturient women treated with BNT162b2 messenger RNA vaccine during All rights reserved. No reuse allowed without permission preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted Passive and active immunity in infants born to mothers with SARS-CoV-2 639 infection during pregnancy: prospective cohort study COVID-19 mRNA vaccines drive differential antibody Fc-functional 642 profiles in pregnant, lactating, and non-pregnant women ReScan, a Multiplex Diagnostic Pipeline, Pans Human Sera for Viral epitope profiling of COVID-19 patients reveals cross-reactivity and 647 correlates of severity Linear epitopes of SARS-CoV-2 spike protein elicit neutralizing antibodies in COVID-19 patients Analysis of SARS-CoV-2 vertical transmission during pregnancy Antibodies in Infants Born to Mothers With COVID-19 Pneumonia Neonatal Early-Onset Infection With SARS-CoV-2 in 33 Neonates Born to Mothers With COVID-19 in Wuhan, China All rights reserved. No reuse allowed without permission preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted Kinetics of maternal pertussis-specific antibodies in infants of mothers 659 vaccinated with tetanus, diphtheria and acellular pertussis (Tdap) during pregnancy Safety and efficacy of PfSPZ Vaccine against Plasmodium falciparum 662 via direct venous inoculation in healthy malaria-exposed adults in Mali: a randomised, 663 double-blind phase 1 trial. The Lancet Infectious Diseases Kinetics of maternal 666 antibodies against rubella and varicella in infants The Neonatal Fc Receptor (FcRn): A Misnomer? Front Immunol 10 Surrogate Virus Neutralization Test and a Longitudinal Study of Antibody Characteristics 672 in COVID-19 Patients The MHC class I-related receptor, FcRn, plays an essential role in the 674 maternofetal transfer of gamma-globulin in humans Short communication: selective placental transport of maternal IgG 677 to the fetus Glycosylation and Placental Transport of Immunoglobulin G All rights reserved. No reuse allowed without permission the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted IgG 684 placental transfer in healthy and pathological pregnancies Update on Transplacental Transfer of IgG Subclasses: Impact of 687 Maternal and Fetal Factors A neutralizing human antibody binds to the N-terminal domain of the Spike 690 protein of SARS-CoV-2 Evaluation of Messenger RNA From COVID-19 BTN162b2 and mRNA-1273 Vaccines in Human Milk All rights reserved. No reuse allowed without permission preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this this version posted We thank all the mothers and infants that participated in this study. We thank Kenneth Scott, All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.The copyright holder for this this version posted December 13, 2021. ; https://doi.org/10.1101/2021.12.09.21267423 doi: medRxiv preprint All rights reserved. No reuse allowed without permission. preprint (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.The copyright holder for this this version posted December 13, 2021. ; https://doi.org/10.1101/2021.12.09.21267423 doi: medRxiv preprint