TY - JOUR
T1 - Placental transfer of SARS-CoV-2 antibodies in mother-neonate pairs
T2 - a prospective nested cohort study
AU - periCOVID-Africa
AU - The PRECISE Network
AU - Mugo, Alex G.
AU - Koech, Angela
AU - Cantrell, Liberty
AU - Mukhanya, Moses
AU - Mwaniki, Isaac
AU - Mutunga, Joseph
AU - Voysey, Merryn
AU - Craik, Rachel
AU - von Dadelszen, Peter
AU - Le Doare, Kirsty
AU - Temmerman, Marleen
AU - Omuse, Geoffrey
AU - Cochet, Madeleine
AU - Rukondo, Gordon
AU - Ouma, Joseph
AU - Hookham, Lauren
AU - Nankabirwa, Victoria
AU - Cose, Stephen
AU - Mboizi, Robert
AU - Etti, Melani
AU - Sommerfelt, Kalvor
AU - Lissauer, Samantha
AU - Kawaza, Kondwani
AU - Freyne, Bridget
AU - Barratt, Benjamin
AU - Carillho, Carla
AU - Pickerill, Kelly
AU - Sandhu, Ash
AU - Tu, Domena
AU - Kinshella, Mai Lei Maggie Woo
AU - Bone, Jeff
AU - Li, Jing Larry
AU - Vidler, Marianne
AU - Krishna, Sanjeev
AU - Whitley, Guy
AU - Cartwright, Judith
AU - Gazeley, Ursula
AU - Akuze, Joseph
AU - Silver, Matt
AU - Lawn, Joy
AU - Filippi, Veronique
AU - Blencowe, Hannah
AU - Noble, Alison
AU - Papageorghiou, Aris
AU - Salisbury, Tatiana
AU - Moore, Sophie
AU - Tribe, Rachel
AU - Poston, Lucilla
AU - Mlambo, Reason
AU - Makacha, Liberty
N1 - Publisher Copyright:
© The Author(s) 2025.
PY - 2025/12
Y1 - 2025/12
N2 - Background: Newborns depend on the transfer of IgG across the placenta to acquire protection against pathogens. We assessed the placental transfer of SARS-CoV-2 antibodies, primarily derived from infection, from seropositive pregnant women enrolled in a pregnancy cohort in Kilifi, Kenya. Methods: The study was nested within a prospective observational multi-country cohort study. All available paired maternal delivery and cord blood samples were selected. Maternal sera were tested for SARS-CoV-2 receptor binding domain (RBD) IgM/IgG total antibodies using the Wantai assay. For positive samples, maternal and corresponding cord blood samples were tested for SARS-CoV-2 IgG antibodies against the spike (anti-spike) and nucleocapsid proteins (anti-NCP) using ELISA kits from Euroimmun. Results: A total of 492 (56.1%) out of 877 maternal delivery samples were positive for RBD IgM/IgG total antibodies. Of these, 416 (84.6%) were seropositive for either anti-NCP IgG, anti-spike IgG antibodies or both. A total of 412 out of 496 (83%) cord blood samples tested positive for either anti-NCP or anti-spike antibodies. The geometric mean ratio was 1.04 (95% CI: 0.90, 1.21), indicating no significant difference between the anti-spike IgG concentration in cord and maternal blood samples. The log-transformed maternal and cord blood anti-spike IgG concentrations showed a weak positive correlation (r = 0.364, n = 496, p < 0.001). No maternal or neonatal factors were associated with the anti-spike IgG placental transfer ratio. Conclusion: Placental transfer of SARS-CoV-2 antibodies was evident in a population of pregnant women whose immunity was primarily derived from infection given the low SARS-CoV-2 vaccine coverage in the study area. The positive correlation between maternal and cord blood anti-spike concentrations suggests that interventions that increase maternal antibody concentrations such as vaccination may increase passive immunity and protection against severe COVID-19 disease in neonates.
AB - Background: Newborns depend on the transfer of IgG across the placenta to acquire protection against pathogens. We assessed the placental transfer of SARS-CoV-2 antibodies, primarily derived from infection, from seropositive pregnant women enrolled in a pregnancy cohort in Kilifi, Kenya. Methods: The study was nested within a prospective observational multi-country cohort study. All available paired maternal delivery and cord blood samples were selected. Maternal sera were tested for SARS-CoV-2 receptor binding domain (RBD) IgM/IgG total antibodies using the Wantai assay. For positive samples, maternal and corresponding cord blood samples were tested for SARS-CoV-2 IgG antibodies against the spike (anti-spike) and nucleocapsid proteins (anti-NCP) using ELISA kits from Euroimmun. Results: A total of 492 (56.1%) out of 877 maternal delivery samples were positive for RBD IgM/IgG total antibodies. Of these, 416 (84.6%) were seropositive for either anti-NCP IgG, anti-spike IgG antibodies or both. A total of 412 out of 496 (83%) cord blood samples tested positive for either anti-NCP or anti-spike antibodies. The geometric mean ratio was 1.04 (95% CI: 0.90, 1.21), indicating no significant difference between the anti-spike IgG concentration in cord and maternal blood samples. The log-transformed maternal and cord blood anti-spike IgG concentrations showed a weak positive correlation (r = 0.364, n = 496, p < 0.001). No maternal or neonatal factors were associated with the anti-spike IgG placental transfer ratio. Conclusion: Placental transfer of SARS-CoV-2 antibodies was evident in a population of pregnant women whose immunity was primarily derived from infection given the low SARS-CoV-2 vaccine coverage in the study area. The positive correlation between maternal and cord blood anti-spike concentrations suggests that interventions that increase maternal antibody concentrations such as vaccination may increase passive immunity and protection against severe COVID-19 disease in neonates.
KW - COVID-19
KW - Efficiency
KW - Placental transfer
KW - SARS-CoV-2 antibodies
KW - Seropositivity
UR - https://www.scopus.com/pages/publications/105010287426
U2 - 10.1186/s12879-025-11225-6
DO - 10.1186/s12879-025-11225-6
M3 - Article
C2 - 40597729
AN - SCOPUS:105010287426
SN - 1471-2334
VL - 25
JO - BMC Infectious Diseases
JF - BMC Infectious Diseases
IS - 1
M1 - 875
ER -
