Seroreactivity against SARS-CoV-2 & Influenza A hemagglutinin among immuneresponding and none-immunresponsive adults and older adults
Author : Jorma Hinkula, Prof. Claudia Devito, Ebba Persson
Abstract :Background: During the respiratory tract infection season 2019/2023, an influenza vaccine study with TIV (VaxiGrip) was conducted on fifty elderly individuals >75 years (75-87 years) and a control group 4-fold increased virus-neutralizing serum activity, HI). Among the non-responding individuals, six individuals with non-significant humoral seroreactivity were selected from each age group. A thorough serological influenza HA-binding assay was performed regarding serum IgG reactivity to the hemagglutinin (HA) antigen in the vaccine at 1 month and 6 months after vaccination. Methods: Serological analys method was performed by ELISA. In brief, Nunc-microplates were coated with 0,25 ug/ml HA1 subtype antigens (A/H1N1/California.p(dm09 eller A/H1N1Michigan. 2015-California-like09.pdm) 0,25 ug/ml (SinoBiologicals, Erlangen, Germany). Total serum and nasal IgA med HRP-rabbit anti-human IgA (Fischer Scientifics H). Subklass IgG1, IgG2, IgG3 och IgG4 analyses with monoklonala antibodies (BAM) specific for humana IgG-subklasses. Detektion with HRP-anti IgG-subklass (BioRad). Inkubations 90 min (vid +37oC, 5% CO2) 0.0003% H2O2/o phanylene diamine-substrate (2mg/mL) i Citratbubert pH5,5. Reaktionsabsorbance 490 nm. Virus neutralization assays and ADCC against Influenza A and SARS CoV-2 viruses performed. Results: In the majority of the studied serum samples the IgG1 subclass was dominant both before and after vaccination. ELISA IgG1 titer increases was only seen after vaccination among individuals responding with a significant HI-serum titer rise.
Keywords :Influenza vaccine, elderly, serological analysis, IgG response, virus-neutralizing activity.
Conference Name :International Conference on Infectious Disease Medicine, Infectious Diseases and Immunotherapy (ICIDMIDI-24)
Conference Place Ouro Preto, Brazil
Conference Date 20th Dec 2024
