@article{83c187815bb040acb3b079e7975526f7,
title = "The magnitude and timing of recalled immunity after breakthrough infection is shaped by SARS-CoV-2 variants",
abstract = "Vaccination against SARS-CoV-2 protects from infection and improves clinical outcomes in breakthrough infections, likely reflecting residual vaccine-elicited immunity and recall of immunological memory. Here, we define the early kinetics of spike-specific humoral and cellular immunity after vaccination of seropositive individuals and after Delta or Omicron breakthrough infection in vaccinated individuals. Early longitudinal sampling revealed the timing and magnitude of recall, with the phenotypic activation of B cells preceding an increase in neutralizing antibody titers. While vaccination of seropositive individuals resulted in robust recall of humoral and T cell immunity, recall of vaccine-elicited responses was delayed and variable in magnitude during breakthrough infections and depended on the infecting variant of concern. While the delayed kinetics of immune recall provides a potential mechanism for the lack of early control of viral replication, the recall of antibodies coincided with viral clearance and likely underpins the protective effects of vaccination against severe COVID-19.",
keywords = "B cell immunity, breakthrough infection, CD4 T cell immunity, CD8 T cell immunity, COVID-19 vaccines, Delta, neutralizing antibodies, Omicron, SARS-CoV-2, vaccination",
author = "Marios Koutsakos and Lee, {Wen Shi} and Arnold Reynaldi and Tan, {Hyon Xhi} and Grace Gare and Paul Kinsella and Liew, {Kwee Chin} and George Taiaroa and Williamson, {Deborah A.} and Kent, {Helen E.} and Eva Stadler and Deborah Cromer and Khoury, {David S.} and Wheatley, {Adam K.} and Juno, {Jennifer A.} and Davenport, {Miles P.} and Kent, {Stephen J.}",
note = "Funding Information: We thank the participants for the generous involvement and provision of samples. We thank T. Amarasena, R. Esterbauer, K. Wragg, P. Konstandopoulos, K. Field, and A. Kelly (University of Melbourne) for excellent technical assistance. We thank molecular staff at the Victorian Infectious Diseases Reference Laboratory for performing RT-PCR. We thank Dr. Julian Druce and Dr. Leon Caly at the Victorian Infectious Diseases Reference Laboratory for isolating and distributing SARS-CoV-2 virus isolates. We acknowledge the Melbourne Cytometry Platform for provision of flow cytometry services. This study was supported by the Australian National Health and Medical Research Council grants 1149990 , 1162760 , and 2004398; Australian Medical Research Future Fund grants 2005544 and 2013870; The Victorian Government; and Australian National Health and Medical Research Council Investigator or Fellowship grants (M.K., A.K.W., J.A.J., H.-X.T., D.A.W., M.P.D., and S.J.K.). Publisher Copyright: {\textcopyright} 2022 Elsevier Inc.",
year = "2022",
month = jul,
day = "12",
doi = "10.1016/j.immuni.2022.05.018",
language = "English",
volume = "55",
pages = "1316--1326.e4",
journal = "Immunity",
issn = "1074-7613",
publisher = "Elsevier",
number = "7",
}
