Background: The immunological bases for the efficacies of the 2 currently licensed influenza vaccines, live attenuated influenza vaccine (LAIV) and inactivated influenza vaccine (IIV), are not fully understood. The goal of this study was to identify specific B-cell responses correlated with the known efficacies of these 2 vaccines.
Methods: We compared the B-cell and antibody responses after immunization with 2010/2011 IIV or LAIV in young adults, focusing on peripheral plasmablasts 6-8 days after vaccination.
Results: The quantities of vaccine-specific plasmablasts and plasmablast-derived polyclonal antibodies (PPAbs) in IIV recipients were significantly higher than those in LAIV recipients. No significant difference was detected in the avidity of vaccine-specific PPAbs between the 2 vaccine groups. Proportionally, LAIV induced a greater vaccine-specific immunoglobulin A plasmablast response, as well as a greater plasmablast response to the conserved influenza nuclear protein, than IIV. The cross-reactive plasmablast response to heterovariant strains, as indicated by the relative levels of cross-reactive plasmablasts and the cross-reactive PPAb binding reactivity, was also greater in the LAIV group.
Conclusions: Distinct quantitative and qualitative patterns of plasmablast responses were induced by LAIV and IIV in young adults; a proportionally greater cross-reactive response was induced by LAIV.
Keywords: B-cell response; antibody; influenza vaccine.
© The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: [email protected].