Live Attenuated Replication-defective Influenza Vaccine
Green Hills Biotechnology is developing a novel vaccine against influenza in a joint project that brings together the expertise of eight different partner institutions both from academia and biotech industry in four European countries and in Russia. The ambitious project is being carried out by the international consortium over a five-year period. The FLUVACC vaccine is a novel component of European systemic efforts to prevent and control influenza, based on a replication deficient virus that is generated by a specialised technique called reverse genetics. The vaccine will be produced in cell culture.
Industrial production of influenza vaccine still relies on traditional techniques. Essentially, chicken eggs are used as mini vaccine factories. They are injected with live influenza virus and incubated for several days so the virus can multiply. The egg is then opened, the virus harvested, purified and inactivated. Unfortunately, highly pathogenic avian viruses do not grow well in eggs as they tend to kill the embryo.
There are many other problems associated with egg-based production. The whole process is time intensive and hard to scale up, so that during a pandemic it may be difficult for supply to meet demand. In addition, the combination of vaccine with egg proteins can lead to allergic reactions in some people.
FLUVACC aims to shift vaccine production away from the traditional methods by generation of live attenuated-replication deficient vaccines that can be produced in cell culture. Instead of using egg-produced viral proteins, the live attenuated vaccines developed by the FLUVACC consortium contain whole replication deficient viruses that generate a strong immune response but are non-pathogenic.[+] Read More
FLUVACC has improved its core technology for live attenuated vaccine production, using a technique called reverse genetics. Together with the project partners, Green Hills Biotechnology has developed a 'master strain' that is lacking the NS1 gene which is essential for productive viral replication. Candidate vaccines for emerging influenza subtypes can be quickly produced by inserting their genes into this master strain so that they express the immunogenic surface proteins, but remain replication-deficient. This master strain was adapted to grow to high titers in tissue culture, making it possible to produce large quantities in the case of a pandemic.
With this project the FLUVACC partners have developed, evaluated and produced several vaccine candidate strains for endemic and pandemic influenza. The vaccine candidates were evaluated in mice and ferrets, and a GMP production process based on Vero cells was developed. Clinical Phase I studies will be performed in the first half of 2007.
The FLUVACC vaccine is as a novel component of European systemic efforts to prevent and control influenza. Influenza is a severe respiratory infection that poses a major health threat on a worldwide scale. The proposed vaccine will reduce mortality and morbidity rates, lost workdays, and hospitalisations.