Long-term persistence of RBD+ memory B cells encoding neutralizing antibodies in SARS-CoV-2 infection
Arunasingam Abayasingam, Harikrishnan Balachandran, David Agapiou, Mohamed Hammoud, Chaturaka Rodrigo, Elizabeth Keoshkerian, Hui Li, Nicholas A. Brasher, Daniel Christ, Romain Rouet, Deborah L. Burnet, Branka Grubor‐Bauk, William D. Rawlinson, Stuart Turville, Anupriya Aggarwal, Alberto Ospina Stella, Christina Fichter, Fabienne Brilot, Michael Mina, Jeffrey J. Post, Bernard Hudson, Nicky Gilroy, Dominic E. Dwyer, Sarah C. Sasson, Fiona Tea, Deepti Pilli, Anthony D. Kelleher, Nicodemus Tedla, Andrew R. Lloyd, Marianne Martinello, Rowena A. Bull
Abstract
Considerable concerns relating to the duration of protective immunity against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) exist, with evidence of antibody titers declining rapidly after infection and reports of reinfection. Here, we monitor the antibody responses against SARS-CoV-2 receptor-binding domain (RBD) for up to 6 months after infection. While antibody titers are maintained, ∼13% of the cohort's neutralizing responses return to background. However, encouragingly, in a selected subset of 13 participants, 12 have detectable RBD-specific memory B cells and these generally are increasing out to 6 months. Furthermore, we are able to generate monoclonal antibodies with SARS-CoV-2 neutralizing capacity from these memory B cells. Overall, our study suggests that the loss of neutralizing antibodies in plasma may be countered by the maintenance of neutralizing capacity in the memory B cell repertoire.