Influenza causes respiratory diseases and often leads to large epidemics. Every year about 290,000 to 650,000 people die due to influenza worldwide. Anti-viral drugs available to treat influenza have many limitations making vaccination the most effective tool to prevent seasonal and pandemic influenza outbreaks. Influenza vaccination is highly recommended for vulnerable people such as individuals above 60 years of age, comorbid individuals having chronic metabolic diseases, pregnant women, and children.
Currently, available influenza vaccines are either inactivated or live attenuated influenza viruses. The prime challenge with existing influenza vaccine is the antigenic diversity and variability that results in accumulation of mutation in antigenic regions and compromises the efficacy of existing influenza vaccines putting threat to the management of influenza. The World Health Organization reviews the global influenza data every year and determines the strain of influenza most likely to circulate next season. This approach makes the influenza vaccine highly predictive and reduces efficacy. The influenza vaccine efficacy seen so far is in between 10 to 60%.
Various approaches are under development to improve the efficacy of influenza vaccines such as the generation of the replication-deficient viruses, use of adjuvants, application of nanotechnologies, virus-like protein particles, recombinant DNA technology, peptide and nucleic acid-based vaccines. Efforts are being made to generate broad-spectrum influenza vaccines, generally known as universal influenza vaccines, that can provide long-lasting protection against a wide variety of influenza strains across all age groups, and eliminate the need of updating influenza vaccine every season.
Another challenge comes from currently used manufacturing technique based on chicken eggs that have the risk of introduction of mutations in the antigen, potential allergy against egg proteins, slow production process. New technologies such as cell-based and plant-based manufacturing approach can overcome most of the limitations associated with egg-based production.
This analyses companies with vaccine candidates and clinical developments for the next generation of influenza vaccine.