Abstract
Influenza virus infections pose a significant threat to public health due to annual seasonal epidemics and occasional pandemics. Influenza is also associated with significant economic losses in animal production. The most effective way to prevent influenza infections is through vaccination. Current vaccine programs rely heavily on the vaccine's ability to stimulate neutralizing antibody responses to the hemagglutinin (HA) protein. One of the biggest challenges to an effective vaccination program lies on the fact that influenza viruses are ever-changing, leading to antigenic drift that results in escape from earlier immune responses. Efforts toward overcoming these challenges aim at improving the strength and/or breadth of the immune response. Novel vaccine technologies, the so-called universal vaccines, focus on stimulating better cross-protection against many or all influenza strains. However, vaccine platforms or manufacturing technologies being tested to improve vaccine efficacy are heterogeneous between different species and/or either tailored for epidemic or pandemic influenza. Here, we discuss current vaccines to protect humans and animals against influenza, highlighting challenges faced to effective and uniform novel vaccination strategies and approaches.
Highlights
Type A (IAV) and type B (IBV) influenza viruses are responsible for yearly epidemics of respiratory disease in humans
Human seasonal influenza infections vary in intensity, from typically mild respiratory disease with dry cough, nasal discharge, rhinitis and pharyngitis, fever, anorexia, and myalgia to occasionally more severe that can lead to secondary bacterial infections and deaths due to pneumonia (Taubenberger and Morens, 2008)
The U.S Flu Vaccine Effectiveness (VE) Network coordinated by the CDC has estimated that the overall, adjusted vaccine effectiveness for influenza seasons from 2005-2016 was between 10 and 60%, with recent studies showing that vaccination reduced the risk of influenza illness by 40–60% when circulating viruses match the vaccine strains (Centers for Disease Control and Prevention, 2017b)
Summary
Type A (IAV) and type B (IBV) influenza viruses are responsible for yearly epidemics of respiratory disease in humans. According to the World Health Organization (WHO), ∼300,000 deaths occur annually worldwide associated with seasonal influenza infections (World Health Organization, 2016). In the U.S, the Centers for Disease Control and Prevention (CDC) estimates that seasonal influenza affects at least 9 million people and results in 12,000–56,000 deaths annually (Centers for Disease Control Prevention, 2017d). Human seasonal influenza infections vary in intensity, from typically mild respiratory disease with dry cough, nasal discharge, rhinitis and pharyngitis, fever, anorexia, and myalgia to occasionally more severe that can lead to secondary bacterial infections and deaths due to pneumonia (Taubenberger and Morens, 2008). H3N2 infections are usually associated with more exacerbated disease than infections with H1N1 or IBVs
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
