Efforts to Improve the Seasonal Influenza Vaccine.

Alfred Harding,Nicholas Heaton

doi:10.3390/vaccines6020019

Abstract

Influenza viruses infect approximately 20% of the global population annually, resulting in hundreds of thousands of deaths. While there are Food and Drug Administration (FDA) approved antiviral drugs for combating the disease, vaccination remains the best strategy for preventing infection. Due to the rapid mutation rate of influenza viruses, vaccine formulations need to be updated every year to provide adequate protection. In recent years, a great amount of effort has been focused on the development of a universal vaccine capable of eliciting broadly protective immunity. While universal influenza vaccines clearly have the best potential to provide long-lasting protection against influenza viruses, the timeline for their development, as well as the true universality of protection they afford, remains uncertain. In an attempt to reduce influenza disease burden while universal vaccines are developed and tested, many groups are working on a variety of strategies to improve the efficacy of the standard seasonal vaccine. This review will highlight the different techniques and technologies that have been, or are being, developed to improve the seasonal vaccination efforts against influenza viruses.

Highlights

The family Orthomyxoviridae is composed of seven genera of negative sense, segmented, single-stranded RNA viruses [1]
Due to the challenges associated with the current Food and Drug Administration (FDA) approved alternative influenza vaccines described above, the use of these vaccines has remained relatively limited when compared to standard egg-grown vaccines
We recently reported a genomic organization for the influenza virus vaccine backbone that can be grown in chicken eggs, yet avoids egg-adaptive mutations [55]

Summary

Introduction

The family Orthomyxoviridae is composed of seven genera of negative sense, segmented, single-stranded RNA viruses [1]. Reassortant viruses must be adapted in eggs to produce high-yield candidate vaccine viruses This process, combined with the need to screen the antigenicity of isolated strains, drastically increases the production time of influenza vaccines for the upcoming season [22,23,24]. Stock viruses infect insect cells in bioreactors to produce recombinant HA protein that is purified and used for vaccination This manufacturing strategy is much quicker since there is no longer a need to rescue influenza viruses and select for high yield variants. This efficiency creates a much more flexible platform, allowing public health officials to potentially adapt to sudden changes in circulating influenza strains. The only additional issue with employing the widespread use of adjuvants like MF59 is the commonly mentioned mild side-effect of enhanced pain at the injection site, likely due to the increased influx of immune cells [49]

Next-Generation Seasonal Influenza Vaccines Currently in Development

Conclusions

Findings

Methods