‘Cell-based’ and ‘egg-based’ refers to how the flu vaccine is made. The traditional way of producing inactivated influenza vaccines is by growing influenza viruses in hens’ eggs (egg-based). When producing the cell-based vaccine, the influenza viruses are grown in cultured cells of mammalian origin in lieu of hens’ eggs.

The traditional technology used to create egg-based flu vaccines is dependent upon an adequate supply of eggs. To create more flexibility in the manufacturing of flu vaccines, cell-based flu vaccines were developed. This is a major advantage in the event of a pandemic in which case, faster production of the vaccine would be required. There’s also a school of thought that cell-based vaccines could have the potential to be more effective than egg-based flu vaccines due to its composition carrying more similarities to the flu viruses that are currently circulating. The idea is, the more similar the vaccine is to the actual virus, the more effective it can be.

Though cell culture technology is relatively new to the manufacturing process for flu vaccines, it is not an unfamiliar resource. Vaccines for rotavirus, polio, smallpox, hepatitis, rubella and chickenpox are all U.S.-licensed vaccines that have been produced using cell culture technology.

The only cell-based flu vaccine currently licensed in the United States is Flucelvax, which we offer in both multi-dose vials and prefilled syringes.