Researchers from the University of Wisconsin-Madison School of Veterinary Medicine have developed a new technology that can enhance effectively the production of vaccines that are able to protect people from influenza B. This technology is in the form of a backbone for the influenza N vaccine virus that will allow vaccine manufacturers to grow vaccine viruses at a faster and increased rate in mammalian cell culture than in eggs. This backbone may be used as a template where vaccine-virus specific components can be added and this could offer some protection against influenza B strains that would usually affect humans.
According to the researchers, they wanted to provide a system that is able to create influenza vaccines effectively. They noted that it is better to yield influenza viruses for vaccine production in cells instead of the usual way of using eggs. The problem, however, is that influenza virus does not grow well in cell cultures when compared to embryonated eggs. The new technology that was discovered may overcome the challenges associated with growing viruses on cells. The results of this study are published in the Proceedings of the National Academy of Sciences.
This new technology will enable vaccine producers to grow vaccine viruses in high yield cell cultures which will then improve seasonal vaccines' ability to protect against influenza viruses A and B. This is because vaccine viruses which are grown in mammalian cell culture will not mutate much as compared to those grown in eggs. Mutations in vaccine viruses will result in inefficiency of the vaccines because mutated viruses in the vaccines can no longer protect against the common virus strains infecting people.
The researchers noted that this method is not perfect but will substantially lead to better vaccines than what we have today. They also commented that there was previously no study that has attempted to produce high-yield influenza B vaccine viruses. In the previous year, the research team also created a high-yield influenza A vaccine virus candidate for cell culture production.
Vaccines virus backbone
According to the CDC, vaccine viruses that are grown in high-yield cell cultures may also lead to faster and greater production of vaccines that can further improve the quality of health services being given to the public, especially in cases of influenza pandemics.
To develop this influenza B vaccine virus backbone, the research team first screened influenza B viruses for random genetic mutations which led to improved replication. Using the mutants as templates, the researchers then attached the genes for the surface proteins that triggered the human response and offered protection in those vaccinated, that is, HA (hemagglutinin) and NA (neuraminidase). They then selected the combinations of backbone mutations that were able to create better growth in cell culture and further identified the two candidate backbones that have led to higher amounts of vaccine virus. they then identified the characteristics of each backbone that have contributed to their higher yield and they found out that the backbones are genetically stable. However they admitted that more testing is needed to find out if they are able to increase virus vaccine yield under industrial conditions.