Effect of Infant RSV Infection on Memory T Cell Responses at Age 2-3 Years.

Background: It is unknown whether RSV infection in infancy alters subsequent RSV immune responses.
Methods: In a nested cohort of healthy, term children, peripheral blood mononuclear cells (PBMCs) were collected at ages 2-3 years to examine RSV memory T cell responses among children previously RSV infected during infancy (first year of life) compared to those RSV-uninfected during infancy. The presence vs . absence of infant RSV infection was determined through a combination of RSV molecular and serologic testing. Memory responses were measured in RSV stimulated PBMCs.
Results: Compared to children not infected with RSV during the first year of life, children infected with RSV during infancy had lower memory T cell responses at ages 2-3 years to in vitro stimulation with RSV for most tested type-1 and type-17 markers for a number of memory T cell subsets.
Conclusions: RSV infection in infancy has long-term effects on memory T cell responses. This is the first study to show the potential for RSV infection in infancy to have long-term effects on the immune memory irrespective of the severity of the infection. Our results suggest a possible mechanism through which infant RSV infection may result in greater risk of subsequent childhood respiratory viral morbidity, findings also relevant to vaccine development.
Competing Interests: LA has served on respiratory syncytial virus (RSV) vaccine advisory boards for Bavarian Nordic, Novavax, Daiichi-Sankyo, ClearPath Vaccines Company, ADVI, and Pfizer. Through Emory University, his laboratory currently receives funding from Pfizer for surveillance studies of RSV infection in adults, from Advaccine Biopharmacueticals Suzhou Co., Ltd. For serologic studies of RSV vaccine recipients, and from Sciogen for animal studies on RSV vaccines. He is a co-inventor on several Centers for Disease Control and Prevention patents on the RSV G protein and its CX3C chemokine motif relative to immune therapy and vaccine development. He is also co-inventor on a patent filing for the use of RSV platform virus-like particles with the F and G proteins for vaccines. TH has served on RSV vaccine advisory boards for Sanofi-Pasteur and Pfizer. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
(Copyright © 2022 Chirkova, Rosas-Salazar, Gebretsadik, Jadhao, Chappell, Peebles, Dupont, Newcomb, Berdnikovs, Gergen, Hartert and Anderson.)