Transplacental transfer of Lassa IgG antibodies in pregnant women in Southern Nigeria: A prospective hospital-based cohort study.

• Published in: PLOS Neglected Tropical Diseases
• Main Authors: Nzelle Delphine Kayem, Sylvanus Okogbenin, Joseph Okoeguale, Joseph Eigbefoh, Joseph Ikheloa, Reuben Eifediyi, Xavier Enodiana, Olugbenga Emmanuel Olorogbogo, Isoken Aikpokpo, Yemisi Ighodalo, Thomas Olokor, George Odigie, Lyndsey Castle, Sophie Duraffour, Lisa Oestereich, Prabin Dahal, Proochista Ariana, Stephan Gunther, Peter Horby
• Format: Article in Journal/Newspaper
• Language: English
• Published: Public Library of Science (PLoS) 2023
• Subjects: Arctic medicine. Tropical medicine; RC955-962; Public aspects of medicine; RA1-1270; Arctic
• Online Access: https://doi.org/10.1371/journal.pntd.0011209; https://doaj.org/article/54defe3329e945fd9635cd19c2c54c4e

Background Evidence from previous studies suggest that Lassa fever, a viral haemorrhagic fever endemic to West Africa has high case fatalities, particularly in pregnancy. While there have been remarkable innovations in vaccine development, with some Lassa vaccines undergoing early clinical trials. An understanding of Lassa antibody kinetics and immune responses will support vaccine design and development. However, there is currently no evidence on the antibody kinetics of Lassa (LASV) in pregnancy. Our study sought to estimate the efficiency of transplacental transfer of LASV IgG antibodies from the mother to the child. Methodology/principal findings The study made use of data from a prospective hospital-based cohort of pregnant women enrolled at the antenatal clinic and followed up at delivery between February and December 2019. Blood samples from mother-child pairs were evaluated for antibodies against Lassa virus. The study demonstrates a transplacental transfer of LASV IgG of 75.3% [60.0-94.0%], with a significant positive correlation between maternal and cord concentrations and a good level of agreement. The study also suggests that transfer may be more variable in women with 'de novo' antibodies compared to those with pre-existing antibodies. Conclusions/significance The study shows that maternal antibody levels play an important role in determining transfer efficiency of Lassa antibodies to the new-born; and while the evidence is preliminary, the study also suggests that transfer efficiency may be less stable in acute or recent infection, as such timing of vaccination before pregnancy, that is in women of childbearing age may be more appropriate for protection of both pregnant women and their neonates.