Quadrivalent influenza shots that are manufactured using virus grown in eggs.
Quadrivalent cell-based influenza shots containing virus grown in cell culture. In place of fertilized chicken eggs, the cell-based vaccine manufacturing process uses animal cells (Madin-Darby Canine Kidney, or MDCK cells) in liquid culture as a host for the growing influenza virus.
Recombinant quadrivalent influenza shot that is an egg-free vaccine
It seems to me that the Quadrivalent cell-based influenza shots being grown in dog cells would make humans more susceptible to cross species infections. It makes you wonder about what is used to make other vaccines.
We should collect the bat carcasses strewn about under the windmills and recycle them as a medium for developing new coronavirus vaccines.