Development and fit-for-purpose verification of an LC-MS method for quantitation of hemagglutinin and neuraminidase proteins in influenza virus-like particle vaccine candidates

Self-Assembled Virus-Like Particle Vaccines via Fluorophilic Interactions Enable Infection Mimicry and Immune Protection

Influenza epidemics persistently threaten global health. Vaccines based on virus-like particles (VLPs), which resemble the native conformation of viruses, have emerged as vaccine candidates. However, the production of VLPs via genetic engineering remains constrained by challenges such as low yields, high costs, and being time consuming. In this study, a novel VLP platform is developed that could mimic infection and confer influenza protection through fluorination-driven self-assembly. The VLPs closely mimick the key steps in viral infection including dendritic cell (DC) attachment and pH-responsive endo-lysosomal escape, which enhances DC maturation and antigen cross-presentation. It is also observed that the VLPs migrate from the injection site to the draining lymph nodes efficiently. Immunization with VLPs triggers both Th1 and Th2 cellular responses, thereby inducing an improved CD8+ T cell response along with strong antigen-specific antibody responses. In several infected mouse models, VLP vaccines ameliorate weight loss, lung virus titers, pulmonary pathologies, and confer full protection against H1N1, H6N2, H9N2, and mixed influenza viruses. Therefore, the results support the potential of VLPs as an effective influenza vaccine with improved immune potency against infection. A methodology to generate VLPs based on fluorophilic interactions, which can be a general approach for development of pathogenic VLPs, is reported.

Overcoming biological barriers by virus-like drug particles for drug delivery

Virus-like particles (VLPs) have natural structural antigens similar to those found in viruses, making them valuable in vaccine immunization. Furthermore, VLPs have demonstrated significant potential in drug delivery, and emerged as promising vectors for transporting chemical drug, genetic drug, peptide/protein, and even nanoparticle drug. With virus-like permeability and strong retention, they can effectively target specific organs, tissues or cells, facilitating efficient intracellular drug release. Further modifications allow VLPs to transfer across various physiological barriers, thus acting the purpose of efficient drug delivery and accurate therapy. This article provides an overview of VLPs, covering their structural classifications, deliverable drugs, potential physiological barriers in drug delivery, strategies for overcoming these barriers, and future prospects.

Characterization of Inactivated Influenza Vaccines Used in the Russian National Immunization Program

BACKGROUND

today's standard quality control methods used to control the protein composition of inactivated influenza vaccines only take into account a few key reference components. They do not allow for thorough characterization of protein compositions. As a result, observation of unpredictable variations in major viral constituents and admixtures of cellular proteins within manufactured vaccines that may seriously influence the immunogenicity and safety of such vaccines has become a pressing issue in vaccinology. This study aims at testing a more sophisticated approach for analysis of inactivated split influenza vaccines licensed in the Russian Federation. The formulations under study are the most available on the market and are included in the Russian National Immunization Program.

METHODS

liquid chromatography with tandem mass spectrometry (LC-MS/MS) analysis, in combination with label-free protein quantitation via the intensity-based absolute-quantitation (iBAQ) algorithm, as well as a number of standard molecular analysis methods, such as sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), dynamic light scattering (DLS), and negative-stain transmission electron microscopy (TEM) were applied.

RESULTS

the methods implemented were able to identify dozens of viral and host proteins and quantify their relative amounts within the final formulations of different commercially available inactivated split influenza vaccines. Investigation of molecular morphology of the vaccine preparations using TEM revealed typical rosettes of major surface proteins (hemagglutinin and neuraminidase). DLS was used to demonstrate a size distribution of the rosettes and to test the stability of vaccine preparations at increased temperatures.

CONCLUSIONS

a holistic approach based on modern, highly productive analytical procedures was for the first time applied for a series of different commercially available inactivated split influenza vaccines licensed in Russia. The protocols probed may be suggested for the post-marketing quality control of vaccines. Comparison of different preparations revealed that the Ultrix® and Ultrix® Quadri vaccines produced by pharmaceutical plant FORT LLC and trivalent vaccine Vaxigrip® produced by pharmaceutical company Sanofi Pasteur have well-organized antigen rosettes, they contain fewer admixture quantities of host cell proteins, and demonstrate good correlation among mostly abundant viral proteins detected by different methods.

Influenza Virus Like Particles (VLPs): Opportunities for H7N9 Vaccine Development

In the midst of the ongoing COVID-19 coronavirus pandemic, influenza virus remains a major threat to public health due to its potential to cause epidemics and pandemics with significant human mortality. Cases of H7N9 human infections emerged in eastern China in 2013 and immediately raised pandemic concerns as historically, pandemics were caused by the introduction of new subtypes into immunologically naïve human populations. Highly pathogenic H7N9 cases with severe disease were reported recently, indicating the continuing public health threat and the need for a prophylactic vaccine. Here we review the development of recombinant influenza virus-like particles (VLPs) as vaccines against H7N9 virus. Several approaches to vaccine development are reviewed including the expression of VLPs in mammalian, plant and insect cell expression systems. Although considerable progress has been achieved, including demonstration of safety and immunogenicity of H7N9 VLPs in the human clinical trials, the remaining challenges need to be addressed. These challenges include improvements to the manufacturing processes, as well as enhancements to immunogenicity in order to elicit protective immunity to multiple variants and subtypes of influenza virus.