Transplacental transfer of Lassa IgG antibodies in pregnant women in Southern Nigeria: a prospective hospital-based cohort study 由 Kayem, ND, Okogbenin, S, Okoeguale, J, Eigbefoh, J, Ikheloa, J, Eifediyi, R, Enodiana, X, Olorogbogo, OE, Aikpokpo, I, Ighodalo, Y, Olokor, T, Odigie, G, Castle, L, Duraffour, S, Oestereich, L, Dahal, P, Ariana, P, Gunther, S, Horby, P