Journal Article

Age-specific differences in the dynamics of protective immunity to influenza

Fang, Vicky J., Cobey, Sarah, Ip, Dennis K. M., Perera, Ranawaka A. P. M., Ranjeva, Sylvia, Leung, Gabriel M., Peiris, J. S. Malik, Subramanian, Rahul, Cowling, Benjamin J.

2019

Overview

Influenza A viruses evolve rapidly to escape host immunity, causing reinfection. The form and duration of protection after each influenza virus infection are poorly understood. We quantify the dynamics of protective immunity by fitting individual-level mechanistic models to longitudinal serology from children and adults. We find that most protection in children but not adults correlates with antibody titers to the hemagglutinin surface protein. Protection against circulating strains wanes to half of peak levels 3.5–7 years after infection in both age groups, and wanes faster against influenza A(H3N2) than A(H1N1)pdm09. Protection against H3N2 lasts longer in adults than in children. Our results suggest that influenza antibody responses shift focus with age from the mutable hemagglutinin head to other epitopes, consistent with the theory of original antigenic sin, and might affect protection. Imprinting, or primary infection with a subtype, has modest to no effect on the risk of non-medically attended infections in adults. Protective immunity after influenza virus infection is poorly understood. Here, the authors quantify the dynamics of immunity against influenza A virus infections by fitting individual-level mechanistic models to longitudinal serology, and find that the form and dynamics of protection differ between children and adults.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 631/114 / 631/250/255/1578 / 692/308/174 / Adolescent / Adult / Adults / Age / Age Factors / Aged / Antibodies, Viral - blood / Antibodies, Viral - immunology / Antigens / Antigens, Viral - immunology / Antigens, Viral - isolation & purification / Child / Child, Preschool / Children / Cross Protection - immunology / Epitopes / Female / Follow-Up Studies / Hemagglutinins / Hemagglutinins - immunology / Hong Kong - epidemiology / Humanities and Social Sciences / Humans / Immune imprinting / Immunity / Immunologic Memory - immunology / Incidence / Infections / Influenza / Influenza A / Influenza A Virus, H1N1 Subtype - immunology / Influenza A Virus, H1N1 Subtype - isolation & purification / Influenza A Virus, H3N2 Subtype - immunology / Influenza A Virus, H3N2 Subtype - isolation & purification / Influenza Vaccines - administration & dosage / Influenza Vaccines - immunology / Influenza, Human - epidemiology / Influenza, Human - immunology / Influenza, Human - prevention & control / Influenza, Human - virology / Longitudinal Studies / Male / Middle Aged / Models, Biological / multidisciplinary / Proteins / Randomized Controlled Trials as Topic / Science / Science (multidisciplinary) / Serology / Time Factors / Viruses / Young Adult