[Development of a novel influenza vaccine derived from a continuous cell line]

Influenza viruses for production are presently produced in embryonated hen"s eggs. This conventional standard methodology is extremely cumbersome; it requires millions of eggs and an extensive purification to reduce the amount of contaminating egg proteins and to minimise the risk of allergies against egg albumin. The shortage of eggs in a pandemic situation, the selection of egg-adapted variants and the presence of adventitious viruses has emphasised the necessity for production of Influenza vaccines on a well characterised stable cell line. Our established serum and protein free Vero cell technology has been successfully adapted to large scale production of a huge variety of Influenza virus strains. The production in 1200 liter fermenter cultures under serum free conditions gave antigen yields comparable to the conventional embryonated egg technology. The development of a rapid and efficient purification scheme resulted in a safe high purity vaccine which was at least as immunogenic as conventional egg-derived vaccines in a mouse model. Clinical trials in the UK, Poland and Austria demonstrated that the Vero cell derived influenza vaccine is well tolerated, safe and highly immunogenic in humans.