Development of a Vero cell-derived influenza whole virus vaccine.

Influenza vaccine production is dependent on the availability of embryonated hen eggs for virus growth. This is an extremely cumbersome system with many disadvantages with respect to selection of virus variants and the presence of adventitious viruses. We have developed an alternative cell culture system which allows rapid production of large volumes of vaccine. The WHO-approved Vero cell line was used in serum-free culture to grow many influenza strains to high titre. This system could be scaled-up to allow vaccine production with a 1200 litre fermenter. A purification scheme was developed which resulted in a high purity whole virus vaccine. This was demonstrated to be at least as immunogenic as a conventional egg-derived preparation.