Sankaranarayanan R, Ha B, Sun H, Liu K, Jadhao S, Hussaini L, McCracken C, Gibson T, Yildirim I, Yi J, Stephens K, Korski C, Kao C, Rostad CA, Anderson EJ, and Anderson LJ
Background: Respiratory syncytial virus (RSV) is a leading cause of acute lower respiratory infections in children <2 years of age. Prior infection in a child is usually determined by RSV antibodies; however, in young children, persisting maternal immunoglobulin G antibodies can incorrectly indicate past RSV infection. We developed and evaluated 4 immunoglobulin A (IgA) antibody enzyme immunoassays (EIAs) with the RSV F, subgroup G (Ga or Gb proteins) or RSV lysate antigens to distinguish infection induced from persisting maternal RSV antibodies., Methods: We tested the EIAs against 62 cord blood specimens (group A), 39 plasma specimens from infants not exposed to an RSV season (group B), 102 plasma specimens from infants with a documented RSV infection (group C), and 124 plasma specimens from infants exposed to their first RSV season but without a documented RSV infection (group D)., Results: Among the 2 negative control groups, no group A specimens and 1 of the group B specimens were positive in all 4 IgA EIAs, giving a specificity of 100% and 97%, respectively. The sensitivity of the F, Ga, Gb, and Lysate IgA EIAs were 88%, 31%, 26%, and 61%, respectively, for group C specimens. Forty-four percent of the 124 specimens in group D were positive in the RSV-F IgA EIA., Conclusions: The RSV-F protein IgA EIA exhibited a high level of sensitivity and specificity for detecting previous RSV infections in the presence of maternal antibodies and can help in RSV clinical trials and epidemiologic studies in young children., Competing Interests: Potential conflicts of interest. L. J. A. has done paid consultancies on RSV vaccines for AstraZeneca, Bavarian Nordic, GSK, and Janssen and on influenza virus vaccines for Pfizer. His laboratory is currently receiving funding through Emory University from Pfizer for RSV surveillance and maternal infant studies and from Advac, Sciogen, and Vernagen for RSV vaccine-related studies. L. J. A. is co-inventor on several Centers for Disease Control and Prevention (CDC) or Emory patents or patent filings on the RSV G protein and its CX3C chemokine motif relative to immune therapy and vaccine development and a patent filing for use of RSV platform VLPs, virus-like particles, with the F and G proteins for vaccines. E. J. A. has consulted for Pfizer, Sanofi Pasteur, GSK, Janssen, Moderna, and Medscape, and his institution receives funds to conduct clinical research unrelated to this manuscript from MedImmune, Regeneron, PaxVax, Pfizer, GSK, Merck, Sanofi Pasteur, Janssen, and Micron. He serves on a safety monitoring board for Kentucky BioProcessing, and Sanofi Pasteur. He serves on a data adjudication board for WCG and ACI Clinical. His institution has also received funding from the National Institutes of Health (NIH) to conduct clinical trials of COVID-19 vaccines. C. A. R. has received institutional research support from Pfizer, BioFire, GSK plc, Janssen Pharmaceuticals, MedImmune, Micron Technology, ModernaTX, Merck & Co, Inc, Novavax, PaxVax, Regeneron, Sanofi Pasteur, CDC, and NIH. She is co-inventor of patented RSV vaccine technology that has been licensed to Meissa Vaccines. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)