This article is a summary, click here for the comprehensive version

There are three types of influenzavirus – A, B and C. Only type A influenzaviruses are associated with pandemics.  An influenza pandemic occurs when a new influenza virus emerges and starts spreading as easily as seasonal influenza.

Influenzaviruses undergo constant genetic mutation (antigen drift). These viruses have a segmented genome. When a cell is infected with two different influenza viruses there is the potential for the new viruses to have a mixture of segments from both parent viruses (antigenic shift). As a result of poor immunity to this novel ‘re-assorted‘ virus, a pandemic can arise as in the case of the Swine flu pandemic in 2009. Swine origin H1N1 had elements of influenzaviruses from both humans, birds and pigs.

The Company is currently developing a ‘universal’, or ‘multi-seasonal’, vaccine for influenzavirus with the aim of providing protection against several strains of influenza A viruses, potentially covering seasonal variation and pandemic outbreaks. The company has identified a number of conserved domains on the proteins M2 and NP and is in the process of selecting which candidate to move to phase I/II clinical trials.

There is no ‘universal’ vaccine currently available. The standard seasonal vaccine is produced annually and the viruses included in this vaccine are based on WHOs recommendations. Some of the challenges to vaccine manufacturers include:

• Licenses for vaccine manufacturing are only granted for one year, which heavily restricts the profitable time on the market for each product.
• Vaccine production in chicken eggs is a lengthy and highly complex process, taking about six months.
• Tight schedules – manufacturers only have a small window of opportunity in which to respond to changes in the WHO recommendation and provide supply
• Risk of mismatch – recommendations for the yearly vaccine composition are issued months before the beginning of the flu season, manufacturers run the constant risk of producing a vaccine that does not match the actual epidemic influenza strain

A multi-seasonal peptide-based vaccine would address many of these challenges