Cell-based vaccines are developed from mammalian cell lines rather than the more common method which uses the cells in embryonicchicken eggs to develop the antigens. The potential use of cell culture techniques in developing viral vaccines has been widely investigated in recent years as a complementary and alternative platform to the current egg-based strategies. Vaccines work to prepare an immune system to fight off disease by generating an immune response to disease-causing agents. This immune response enables the immune system to act more quickly and effectively when exposed to that antigen again, and is the most effective tool to date to prevent the spread of infectious diseases.
Production of cell-based vaccines
To produce viral vaccines, candidate vaccine viruses are grown in mammalian tissue culture of cells with a finite lifespan. These cells are typically Madin-Darby Canine Kidney cells, but others are also used including: Vero, Human diploid cell lines WI-38 and MRC 5, PerC6 and PMK cells. The candidate vaccine virus strain will replicate using the mammalian cells. Next, the virus is extracted from the cells in the liquid culture, purified, then tested or modified for the specific vaccine being produced.
Advantages of cell lines
The main benefit of cell-based vaccines is the ability to rapidly produce vaccine supplies during an impending pandemic. Cell-based antigen production may offer a faster and more stable production of vaccines compared to embryonic chicken eggs, which produce 1-2 vaccine doses per chicken egg. Though host cells replicate well in chicken eggs, vaccine production with mammalian cells would not rely on an adequate supply of chicken eggs to produce each vaccine. In addition, cell-based vaccines may allow for multiple viral vaccines be produced in the same production platforms and facilities in a more sterile environment. In addition, some strains do not grow well on embryonic chicken eggs. Cell lines can be grown in synthetic media avoiding animal serum which may pose a sterility problem, more specifically, it prevents the spread of transmissible spongiform encephalopathies. Other benefits are the avoidance of egg-based allergy reactions. Egg-based vaccine development may also create viral changes which make antibodies resulting from the vaccine less directly effective than cell-based vaccines
, produced by Novartis, was approved by the European Medicines Agency in 2009, for use in countries affiliated with the European Union. Optaflu is nearly identical to Flucelvax; it is also produced in Madin-Darby canine kidney cells and targets the same Influenza subtypes. The main differences are in release specifications for measuring vaccine lots' safety, efficacy, and quality, mostly due to differences between U.S. and European regulatory standards and tests.
