RESUMEN
BACKGROUND: Preexisting immunity, including memory B cells and preexisting antibodies, can modulate antibody responses to influenza in vivo to antigenically related antigens. We investigated whether preexisting hemagglutination inhibition (HAI) antibodies targeting the K163 epitope on the hemagglutinin (K163 antibodies) could affect antibody responses following vaccination with A/California/07/2009-like A(H1N1)pdm09 influenza viruses in humans. METHODS: Pre- and postvaccination sera collected from 300 adults (birth years, 1961-1998) in 6 seasons (2010-2016) were analyzed by HAI assays with 2 reverse genetics viruses and A(H1N1) viruses circulated from 1977 to 2018. Antibody adsorption assays were used to verify the preexisting K163 antibody-mediated suppression effect. RESULTS: Preexisting K163 antibody titers ≥80 affected HAI antibody responses following influenza vaccination containing A/California/07/2009-like antigens. At high K163 antibody concentrations (HAI antibody titers ≥160), all HAI antibody responses were suppressed. However, at moderate K163 antibody concentrations (HAI antibody titer, 80), only K163 epitope-specific antibody responses were suppressed, and novel HAI antibody responses targeting the non-K163 epitopes were induced by vaccination. Novel antibodies targeting non-K163 epitopes cross-reacted with newly emerging A(H1N1)pdm09 strains with a K163Q mutation rather than historic 1977-2007 A(H1N1) viruses. CONCLUSIONS: K163 antibody-mediated suppression shapes antibody responses to A(H1N1)pdm09 vaccination. Understanding how preexisting antibodies suppress and redirect vaccine-induced antibody responses is of great importance to improve vaccine effectiveness.
Asunto(s)
Subtipo H1N1 del Virus de la Influenza A , Vacunas contra la Influenza , Gripe Humana , Adulto , Humanos , Inmunidad Humoral , Anticuerpos Antivirales , Vacunación , Pruebas de Inhibición de Hemaglutinación , EpítoposRESUMEN
The rapid development of the SARS-CoV-2 vaccine has been used to prevent the spread of coronavirus 2019 (COVID-19). However, the ongoing and future pandemics caused by SARS-CoV-2 variants and mutations underscore the need for effective vaccines that provide broad-spectrum protection. Here, we developed a nanoparticle vaccine with broad protection against divergent SARS-CoV-2 variants. The corresponding conserved epitopes of the preexisting neutralizing (CePn) antibody were presented on a self-assembling Helicobacter pylori ferritin to generate the CePnF nanoparticle. Intranasal immunization of mice with CePnF nanoparticles induced robust humoral, cellular, and mucosal immune responses and a long-lasting immunity. The CePnF-induced antibodies exhibited cross-reactivity and neutralizing activity against different coronaviruses (CoVs). CePnF vaccination significantly inhibited the replication and pathology of SARS-CoV-2 Delta, WIV04, and Omicron strains in hACE2 transgenic mice and, thus, conferred broad protection against these SARS-CoV-2 variants. Our constructed nanovaccine targeting the conserved epitopes of the preexisting neutralizing antibodies can serve as a promising candidate for a universal SARS-CoV-2 vaccine.
Asunto(s)
Anticuerpos Neutralizantes , Vacunas contra la COVID-19 , COVID-19 , Epítopos , Nanopartículas , SARS-CoV-2 , Animales , Anticuerpos Neutralizantes/inmunología , SARS-CoV-2/inmunología , Ratones , COVID-19/prevención & control , COVID-19/inmunología , COVID-19/virología , Nanopartículas/química , Vacunas contra la COVID-19/inmunología , Epítopos/inmunología , Epítopos/química , Humanos , Anticuerpos Antivirales/inmunología , Ratones Transgénicos , Femenino , Ratones Endogámicos BALB C , NanovacunasRESUMEN
Aim: Preexisting anti-polyethylene glycol (PEG) antibodies (APAs) may affect the efficacy and safety of PEGylated compounds. Omontys® and Krystexxa® withdrawal and SARS-CoV-2 RNA vaccine anaphylaxis have all been linked to APAs. This project aimed to develop and validate a method to detect total antibodies against PEG, pre- and post-dose. Materials & methods: The repetitive, linear PEG structure prevented the use of a bridging homogenous format, hence the requirement to use a solid-phase extraction and acid dissociation assay coupled with the Meso Scale Discovery® platform. Results & conclusion: Using singlicate analysis, the method was validated to successfully detect APA pre- and post-dose, with a crucial aspect of the method being the preparation of an appropriate negative control.