Boulder Q: Is there any work going on towards developing vaccines in cultures besides eggs, since many people are allergic to eggs, and therefore can be immunized?
Yes, a lot, both for your reason, and to increase vaccine yield and shorten the time to make it. Viruses may be grown in cell culture instead of eggs, so many people are trying to optimize that process. Also, just the key antigens can be expressed in harmless bacteria or yeast which make them and release them into the medium. Many drugs are already made this way.