An Overview of Influenza Viruses and Vaccines

Abstract

Influenza remains one of the major public health concerns because it causes annual epidemics and can potentially instigate a global pandemic. Numerous countermeasures, including vaccines and antiviral treatments, are in use against seasonal influenza infection; however, their effectiveness has always been discussed due to the ongoing resistance to antivirals and relatively low and unpredictable efficiency of influenza vaccines compared to other vaccines. The growing interest in vaccines as a promising approach to prevent and control influenza may provide alternative vaccine development options with potentially increased efficiency. In addition to currently available inactivated, live-attenuated, and recombinant influenza vaccines on the market, novel platforms such as virus-like particles (VLPs) and nanoparticles, and new vaccine formulations are presently being explored. These platforms provide the opportunity to design influenza vaccines with improved properties to maximize quality, efficacy, and safety. The influenza vaccine manufacturing process is also moving forward with advancements relating to egg- and cell-based production, purification processes, and studies into the physicochemical attributes and vaccine degradation pathways. These will contribute to the design of more stable, optimized vaccine formulations guided by contemporary analytical testing methods and via the implementation of the latest advances in the field.

Algal and Cyanobacterial Lectins and Their Antimicrobial Properties

“…Human influenza A and B viruses are highly contagious and are primarily responsible for the seasonally acute respiratory disease that outbreaks and spreads worldwide, giving rise to increased hospital admission and mortality. However, attention is focused mainly on influenza type A because it is by far the most virulent and causes severe respiratory disease or death [92,93].…”

Incidence, Disease Severity, and Follow-Up of Influenza A/A, A/B, and B/B Virus Dual Infections in Children: A Hospital-Based Digital Surveillance Program

“…According to the latest International Committee on Taxonomy of Viruses’ (ICTV) Virus Taxonomy Release ratified in March 2021, the Orthomyxoviridae family comprises seven genera and nine species, including Influenza A virus (IAV), Influenza B virus (IBV), Influenza C virus (ICV), and Influenza D virus (IDV) [ 4 ]. IDV and ICV may be associated with mild or asymptomatic infection in humans [ 5 , 6 , 7 ] whereas IAV and IBV infection can cause severe and fatal diseases [ 2 , 8 ]. IAVs are further divided into subtypes based on their surface proteins hemagglutinin (H) and neuraminidase (N), of which A(H1N1)pdm09 and A(H3N2) are currently circulating amongst humans.…”

“…IAVs are further divided into subtypes based on their surface proteins hemagglutinin (H) and neuraminidase (N), of which A(H1N1)pdm09 and A(H3N2) are currently circulating amongst humans. IBVs are further classified into two distinct lineages, B/Victoria and B/Yamagata [ 8 ]. IAV subtypes and IBV lineages are antigenically different.…”

Neuraminidase Inhibitor of Garcinia atroviridis L. Fruits and Leaves Using Partial Purification and Molecular Characterization

“…Globally, annual seasonal influenza epidemics are predicted to result in approximately 3 to 5 million cases of severe illness, and 290,000 to 650,000 respiratory-related deaths [ 1 ]. Among the four genera of influenza viruses (influenza types A, B, C, and D), type A is the most pathogenic group of viruses capable of causing severe respiratory illnesses or death [ 2 ]. The 2009 swine flu H1N1 and the highly pathogenic avian flu H5N1 are among influenza A viruses that have posed significant health risks in many parts of the world.…”

“…Furthermore, HA aids in the virus’s internalization into the host cell via endocytosis, delivering the nucleoprotein into the cytoplasm. NA functions as a biological scissor, cleaving sialic acid residues from HA and cell surface glycans and facilitating virus movement during entry, and from the surface glycoprotein of newly synthesized virions, allowing the virus to be released from the host and spread to other cells [ 2 ].…”