avianize

verb2

1. •
   (rare) To make avian; to make bird-like or into a bird.
2. •
   To attenuate (something such as a virus, for example for use in a vaccine) by repeatedly culturing it in bird embryos.

   • In Japan a lapinized/avianized vaccine was developed which was used extensively to control the disease in Asia. [.].. The Onderstepoort strain was attenuated by growth in avian cells [...] — 1994